diff --git a/src/pages/index.vue b/src/pages/index.vue
index 9f4cb37..e189c42 100644
--- a/src/pages/index.vue
+++ b/src/pages/index.vue
@@ -1283,7 +1283,7 @@ export default {
       await Promise.all([this.downloadData(), this.loadConfig()]);
     },
 
-    async downloadData() {
+    async downloadData(forceClear = false) {
       if (this.loading.download) return;
 
       try {
@@ -1296,8 +1296,8 @@ export default {
           if (response.error.code === "NOT_FOUND") {
             this.state.showNoDataMessage = true;
             this.state.noDataMessage = response.error.message;
-            // 只有当前没有数据时才设置为空，避免覆盖已有的本地数据
-            if (!this.state.boardData || (!this.state.boardData.homework && !this.state.boardData.attendance)) {
+            // 如果强制清空或当前没有数据时才设置为空
+            if (forceClear || !this.state.boardData || (!this.state.boardData.homework && !this.state.boardData.attendance)) {
               this.state.boardData = {
                 homework: {},
                 attendance: { absent: [], late: [], exclude: [] },
@@ -1320,11 +1320,11 @@ export default {
           this.$message.success("下载成功", "数据已更新");
         }
       } catch (error) {
-        // 数据加载失败时不覆盖现有数据，只显示错误信息
+        // 数据加载失败时的处理
         console.error("数据加载失败:", error);
         this.$message.error("下载失败", error.message);
-        // 如果当前没有任何数据，才初始化为空数据
-        if (!this.state.boardData || (!this.state.boardData.homework && !this.state.boardData.attendance)) {
+        // 如果强制清空或当前没有任何数据，才初始化为空数据
+        if (forceClear || !this.state.boardData || (!this.state.boardData.homework && !this.state.boardData.attendance)) {
           this.state.boardData = {
             homework: {},
             attendance: { absent: [], late: [], exclude: [] },
@@ -1615,8 +1615,8 @@ export default {
             })
             .catch(() => {});
 
-          // Load both data and subjects in parallel
-          await Promise.all([this.downloadData(), this.loadSubjects()]);
+          // Load both data and subjects in parallel, force clear data when switching dates
+          await Promise.all([this.downloadData(true), this.loadSubjects()]);
         }
       } catch (error) {
         console.error("Date processing error:", error);