diff --git a/apps/desktop/src/components/grid/DataGrid.vue b/apps/desktop/src/components/grid/DataGrid.vue
index accd57cc2..e7bec3175 100644
--- a/apps/desktop/src/components/grid/DataGrid.vue
+++ b/apps/desktop/src/components/grid/DataGrid.vue
@@ -131,7 +131,8 @@ import { dataGridHeaderContentWidth, scrollbarGutterWidth } from "@/lib/dataGrid
 import { canGoNextDataGridPage } from "@/lib/dataGrid/dataGridPagination";
 import { dataGridCountQueryOptions } from "@/lib/dataGrid/dataGridQueryOptions";
 import { dataGridBottomScrollTop, dataGridScrollPosition, isDataGridAtScrollBottom, isDataGridNearScrollBottom, shouldCheckInfiniteScrollAfterScroll, type DataGridScrollPosition } from "@/lib/dataGrid/dataGridInfiniteScroll";
-import { CANVAS_DATA_GRID_ROW_HEIGHT, drawCanvasDataGrid } from "@/lib/dataGrid/canvasDataGridRenderer";
+import { CANVAS_DATA_GRID_ROW_HEIGHT, dataGridSearchMatchKey, drawCanvasDataGrid } from "@/lib/dataGrid/canvasDataGridRenderer";
+import { createRowLowerTextCache } from "@/lib/dataGrid/dataGridRowLowerText";
 import { dataGridPreviewLabelKey, dataGridSaveActionMode, dataGridSaveToolbarState } from "@/lib/dataGrid/dataGridSaveUi";
 import type { QueryEditabilityReason } from "@/lib/sql/sqlAnalysis";
 import { EDITOR_FONT_FAMILY_CSS_VAR } from "@/lib/editor/editorThemes";
@@ -558,7 +559,7 @@ const dataGridSearch = useDataGridSearch({
   columns: () => props.result.columns,
   suggestionColumns: () => props.tableMeta?.columns.map((column) => column.name) ?? props.result.columns,
   rows: () => displayItems.value,
-  getCellText: (row, columnIndex) => (row.data[columnIndex] === null ? "" : formatCellCached(row.data[columnIndex], columnIndex)),
+  getCellSearchText: (row, columnIndex) => (row.data[columnIndex] === null ? "" : rowLowerTextCache.get(row.data, columnIndex)),
   onNavigate: () => nextTick(scrollToCurrentMatch),
 });
 const { searchText, deferredSearchText: deferredClientSearchText, overlayVisible: searchOverlayVisible, currentMatchIndex, suggestions: searchSuggestions, suggestionIndex, matches: searchMatches, matchSet: searchMatchSet, currentMatch: currentSearchMatch } = dataGridSearch;
@@ -3061,7 +3062,7 @@ const sortedRows = computed(() => {
     const rows = props.result.rows;
     indices = indices.filter((sourceIndex) => {
       const data = rows[sourceIndex];
-      return data.some((cell, columnIndex) => cell !== null && formatCellCached(cell, columnIndex).toLowerCase().includes(q));
+      return data.some((cell, columnIndex) => cell !== null && rowLowerTextCache.get(data, columnIndex).includes(q));
     });
   }
   return indices;
@@ -3203,7 +3204,7 @@ watch(
 
 function cellIsSearchMatch(displayRow: number, col: number): boolean {
   if (isScrolling.value) return false;
-  return searchMatchSet.value.has(`cell:${displayRow}:${col}`);
+  return searchMatchSet.value.has(dataGridSearchMatchKey(displayRow, col));
 }
 
 function cellIsCurrentMatch(displayRow: number, col: number): boolean {
@@ -3217,7 +3218,7 @@ function cellIsCurrentMatch(displayRow: number, col: number): boolean {
 // maps to the field row header at the field's column index.
 function transposeHeaderIsSearchMatch(fieldIndex: number): boolean {
   if (isScrolling.value) return false;
-  return searchMatchSet.value.has(`column:-1:${fieldIndex}`);
+  return searchMatchSet.value.has(dataGridSearchMatchKey(-1, fieldIndex));
 }
 
 function transposeHeaderIsCurrentMatch(fieldIndex: number): boolean {
@@ -4148,6 +4149,9 @@ const resolvedColumnFormatters = computed(() => props.result.columns.map((_, col
 const columnFormatterSignatures = computed(() => resolvedColumnFormatters.value.map(formatterSignature));
 const primitiveCellFormatCache = new Map<string, string>();
 let objectCellFormatCache = new WeakMap<object, Map<number, string>>();
+// 搜索用小写文本缓存：按行数组身份挂 WeakMap（工作集=当前结果行，GC 回收），
+// 不用固定容量 LRU——搜索是全量顺序扫描，超限修剪会导致第二遍零命中抖动
+const rowLowerTextCache = createRowLowerTextCache(formatCellCached);
 
 function formatterSignature(formatter: ColumnFormatterConfig | undefined): string {
   return formatter ? JSON.stringify(formatter) : "";
@@ -4156,6 +4160,7 @@ function formatterSignature(formatter: ColumnFormatterConfig | undefined): strin
 function clearCellFormatCache() {
   primitiveCellFormatCache.clear();
   objectCellFormatCache = new WeakMap<object, Map<number, string>>();
+  rowLowerTextCache.clear();
 }
 
 function rememberPrimitiveCellFormat(key: string, display: string): string {
diff --git a/apps/desktop/src/composables/__tests__/useDataGridSearch.spec.ts b/apps/desktop/src/composables/__tests__/useDataGridSearch.spec.ts
index 4340ca5f0..e1714a640 100644
--- a/apps/desktop/src/composables/__tests__/useDataGridSearch.spec.ts
+++ b/apps/desktop/src/composables/__tests__/useDataGridSearch.spec.ts
@@ -5,19 +5,34 @@ import { useDataGridSearch } from "@/composables/useDataGridSearch";
 describe("useDataGridSearch", () => {
   it("debounces matching across columns and cells", async () => {
     vi.useFakeTimers();
-    const search = useDataGridSearch({ columns: ["id", "name"], rows: [[1, "Alice"]], getCellText: (row, column) => String(row[column] ?? "") });
+    // getCellSearchText 契约：返回小写文本（调用方负责缓存小写副本）
+    const search = useDataGridSearch({ columns: ["id", "name"], rows: [[1, "Alice"]], getCellSearchText: (row, column) => String(row[column] ?? "").toLowerCase() });
     search.searchText.value = "ali";
     await nextTick();
     expect(search.matches.value).toEqual([]);
     vi.advanceTimersByTime(150);
     await nextTick();
     expect(search.matches.value).toEqual([{ kind: "cell", displayRow: 0, col: 1 }]);
+    // matchSet 用数值 key：(displayRow+1)*65536+col
+    expect(search.matchSet.value.has((0 + 1) * 65536 + 1)).toBe(true);
+    vi.useRealTimers();
+  });
+
+  it("keys column-name matches with displayRow -1", async () => {
+    vi.useFakeTimers();
+    const search = useDataGridSearch({ columns: ["id", "name"], rows: [], getCellSearchText: () => "" });
+    search.searchText.value = "nam";
+    await nextTick();
+    vi.advanceTimersByTime(150);
+    await nextTick();
+    expect(search.matches.value).toEqual([{ kind: "column", displayRow: -1, col: 1 }]);
+    expect(search.matchSet.value.has((-1 + 1) * 65536 + 1)).toBe(true);
     vi.useRealTimers();
   });
 
   it("suggests columns and replaces only the active token", async () => {
     const columns = ref(["customer_id", "created_at"]);
-    const search = useDataGridSearch({ columns, rows: [], getCellText: () => "" });
+    const search = useDataGridSearch({ columns, rows: [], getCellSearchText: () => "" });
     search.searchText.value = "status = cus";
     await nextTick();
     expect(search.suggestions.value).toEqual(["customer_id"]);
diff --git a/apps/desktop/src/composables/useDataGridSearch.ts b/apps/desktop/src/composables/useDataGridSearch.ts
index 9fc8480fa..7b2233c29 100644
--- a/apps/desktop/src/composables/useDataGridSearch.ts
+++ b/apps/desktop/src/composables/useDataGridSearch.ts
@@ -1,4 +1,5 @@
 import { computed, getCurrentScope, nextTick, onScopeDispose, ref, toValue, watch, type MaybeRefOrGetter } from "vue";
+import { dataGridSearchMatchKey } from "@/lib/dataGrid/canvasDataGridRenderer";
 
 export type DataGridSearchMatch = {
   kind: "cell" | "column";
@@ -10,7 +11,9 @@ export type UseDataGridSearchOptions<Row> = {
   columns: MaybeRefOrGetter<readonly string[]>;
   suggestionColumns?: MaybeRefOrGetter<readonly string[]>;
   rows: MaybeRefOrGetter<readonly Row[]>;
-  getCellText: (row: Row, columnIndex: number) => string;
+  /** 必须返回小写文本（查询词已小写）。调用方可据此缓存小写副本，
+   * 避免每次按键对全部单元格重新分配 toLowerCase 字符串。 */
+  getCellSearchText: (row: Row, columnIndex: number) => string;
   debounceMs?: number;
   onNavigate?: (match: DataGridSearchMatch) => void;
 };
@@ -38,12 +41,13 @@ export function useDataGridSearch<Row>(options: UseDataGridSearchOptions<Row>) {
     });
     toValue(options.rows).forEach((row, displayRow) => {
       columns.forEach((_, col) => {
-        if (options.getCellText(row, col).toLowerCase().includes(query)) result.push({ kind: "cell", displayRow, col });
+        if (options.getCellSearchText(row, col).includes(query)) result.push({ kind: "cell", displayRow, col });
       });
     });
     return result;
   });
-  const matchSet = computed(() => new Set(matches.value.map((match) => `${match.kind}:${match.displayRow}:${match.col}`)));
+  // 数值 key（列头匹配 displayRow=-1），避免每匹配一次字符串拼接
+  const matchSet = computed(() => new Set(matches.value.map((match) => dataGridSearchMatchKey(match.displayRow, match.col))));
   const currentMatch = computed(() => matches.value[currentMatchIndex.value] ?? null);
 
   function clearTimer() {
diff --git a/apps/desktop/src/lib/dataGrid/canvasDataGridRenderer.ts b/apps/desktop/src/lib/dataGrid/canvasDataGridRenderer.ts
index 7f8ab5440..142114ee9 100644
--- a/apps/desktop/src/lib/dataGrid/canvasDataGridRenderer.ts
+++ b/apps/desktop/src/lib/dataGrid/canvasDataGridRenderer.ts
@@ -25,6 +25,13 @@ export interface CanvasEditingCell {
   col: number;
 }
 
+/** 搜索匹配的数值 key：列头匹配 displayRow 为 -1。相比字符串拼接 key，
+ * 每次按键构建 matchSet、每帧对可见单元格查询都零字符串分配。
+ * ponytail: 列数上限 65536，网格列数远达不到 */
+export function dataGridSearchMatchKey(displayRow: number, col: number): number {
+  return (displayRow + 1) * 65536 + col;
+}
+
 export interface CanvasSearchMatch {
   kind: "cell" | "column";
   displayRow: number;
@@ -50,7 +57,7 @@ export interface DrawCanvasDataGridOptions {
   hoverCell: CanvasHoverCell | null;
   isScrolling: boolean;
   editingCell: CanvasEditingCell | null;
-  searchMatchKeys: ReadonlySet<string>;
+  searchMatchKeys: ReadonlySet<number>;
   currentSearchMatch: CanvasSearchMatch | null;
   formatCell: (value: CellValue, columnIndex: number) => string;
   draftCellPlaceholder?: string;
@@ -334,7 +341,7 @@ export function drawCanvasDataGrid(options: DrawCanvasDataGridOptions) {
       const isDirtyCell = item.isDirtyCol[actualColIdx];
       const selectedFillVisual = rowSelectionVisual || selectedCell;
       const selectedBorderVisual = rowSelectionVisual || selectedCell;
-      const isSearchMatch = paintSearchMatches && searchMatchKeys.has(`cell:${item.displayIndex}:${actualColIdx}`);
+      const isSearchMatch = paintSearchMatches && searchMatchKeys.has(dataGridSearchMatchKey(item.displayIndex, actualColIdx));
       const isCurrentSearchMatch = paintSearchMatches && currentSearchMatch?.displayRow === item.displayIndex && currentSearchMatch.col === actualColIdx;
       const clippedX = Math.max(drawX, rowNumberWidth);
       const cellPaintWidth = Math.min(width, drawX + colWidth) - clippedX;
diff --git a/apps/desktop/src/lib/dataGrid/dataGridRowLowerText.ts b/apps/desktop/src/lib/dataGrid/dataGridRowLowerText.ts
new file mode 100644
index 000000000..147f819b8
--- /dev/null
+++ b/apps/desktop/src/lib/dataGrid/dataGridRowLowerText.ts
@@ -0,0 +1,38 @@
+import type { CellValue } from "@/lib/dataGrid/cellValue";
+
+type RowLowerTextEntry = {
+  /** 每列缓存时的源值引用：单元格被原地编辑后引用不再相等，仅重算该格 */
+  values: CellValue[];
+  lowers: (string | undefined)[];
+};
+
+/**
+ * 搜索用小写文本缓存，按行数组身份挂 WeakMap：
+ * - 工作集天然等于当前在内存中的结果行（行数组是 markRaw 的稳定引用），
+ *   不存在固定容量 LRU 在全量顺序扫描下的零命中抖动，GC 自动回收旧结果；
+ * - 展示格式化器/列类型变化时由调用方 clear() 整体失效。
+ */
+export function createRowLowerTextCache(format: (value: CellValue, columnIndex: number) => string) {
+  let cache = new WeakMap<object, RowLowerTextEntry>();
+
+  function get(rowData: CellValue[], columnIndex: number): string {
+    let entry = cache.get(rowData);
+    if (!entry) {
+      entry = { values: [], lowers: [] };
+      cache.set(rowData, entry);
+    }
+    const value = rowData[columnIndex];
+    const cached = entry.lowers[columnIndex];
+    if (cached !== undefined && Object.is(entry.values[columnIndex], value)) return cached;
+    const lower = format(value, columnIndex).toLowerCase();
+    entry.values[columnIndex] = value;
+    entry.lowers[columnIndex] = lower;
+    return lower;
+  }
+
+  function clear() {
+    cache = new WeakMap<object, RowLowerTextEntry>();
+  }
+
+  return { get, clear };
+}
diff --git a/packages/app-tests/dataGridRowLowerText.test.ts b/packages/app-tests/dataGridRowLowerText.test.ts
new file mode 100644
index 000000000..be4f19c94
--- /dev/null
+++ b/packages/app-tests/dataGridRowLowerText.test.ts
@@ -0,0 +1,53 @@
+import { strict as assert } from "node:assert";
+import { test } from "vitest";
+import { createRowLowerTextCache } from "../../apps/desktop/src/lib/dataGrid/dataGridRowLowerText.ts";
+import type { CellValue } from "../../apps/desktop/src/lib/dataGrid/cellValue.ts";
+
+test("memoizes lowercase text per cell across repeated full scans", () => {
+  let formatCalls = 0;
+  const cache = createRowLowerTextCache((value) => {
+    formatCalls++;
+    return String(value);
+  });
+  const rows: CellValue[][] = Array.from({ length: 1000 }, (_, i) => [i, `Name-${i}`, `MAIL${i}@X.COM`]);
+
+  // 第一遍全量扫描：每格格式化一次
+  for (const row of rows) for (let col = 0; col < 3; col++) cache.get(row, col);
+  assert.equal(formatCalls, 3000);
+  assert.equal(cache.get(rows[0]!, 2), "mail0@x.com");
+
+  // 第二遍相同顺序扫描：必须全部命中（固定容量 LRU 在此场景会零命中）
+  for (const row of rows) for (let col = 0; col < 3; col++) cache.get(row, col);
+  assert.equal(formatCalls, 3000);
+});
+
+test("recomputes only the edited cell after in-place mutation", () => {
+  let formatCalls = 0;
+  const cache = createRowLowerTextCache((value) => {
+    formatCalls++;
+    return String(value);
+  });
+  const row: CellValue[] = ["A", "B"];
+  assert.equal(cache.get(row, 0), "a");
+  assert.equal(cache.get(row, 1), "b");
+  assert.equal(formatCalls, 2);
+
+  // 保存后原地写回单元格：仅该格重算
+  row[0] = "Changed";
+  assert.equal(cache.get(row, 0), "changed");
+  assert.equal(cache.get(row, 1), "b");
+  assert.equal(formatCalls, 3);
+});
+
+test("clear() invalidates everything (formatter/column-type changes)", () => {
+  let formatCalls = 0;
+  const cache = createRowLowerTextCache((value) => {
+    formatCalls++;
+    return String(value);
+  });
+  const row: CellValue[] = ["X"];
+  cache.get(row, 0);
+  cache.clear();
+  cache.get(row, 0);
+  assert.equal(formatCalls, 2);
+});