diff --git a/web/messages/en.json b/web/messages/en.json
index 7eb1a2c..3197edb 100644
--- a/web/messages/en.json
+++ b/web/messages/en.json
@@ -44,7 +44,9 @@
       "maxStepsOfPlan": "Max steps of a research plan",
       "maxStepsDescription": "By default, each research plan has 3 steps.",
       "maxSearchResults": "Max search results",
-      "maxSearchResultsDescription": "By default, each search step has 3 results."
+      "maxSearchResultsDescription": "By default, each search step has 3 results.",
+      "enableWebSearch": "Enable web search",
+      "enableWebSearchDescription": "When disabled, only local RAG knowledge base will be used. Useful for environments without internet access."
     },
     "mcp": {
       "title": "MCP Servers",
diff --git a/web/messages/zh.json b/web/messages/zh.json
index d74b11f..f77cc24 100644
--- a/web/messages/zh.json
+++ b/web/messages/zh.json
@@ -44,7 +44,9 @@
       "maxStepsOfPlan": "研究计划的最大步骤数",
       "maxStepsDescription": "默认情况下，每个研究计划有 3 个步骤。",
       "maxSearchResults": "最大搜索结果数",
-      "maxSearchResultsDescription": "默认情况下，每个搜索步骤有 3 个结果。"
+      "maxSearchResultsDescription": "默认情况下，每个搜索步骤有 3 个结果。",
+      "enableWebSearch": "启用网络搜索",
+      "enableWebSearchDescription": "禁用后将仅使用本地 RAG 知识库。适用于无网络环境。"
     },
     "mcp": {
       "title": "MCP 服务器",
diff --git a/web/src/app/settings/tabs/general-tab.tsx b/web/src/app/settings/tabs/general-tab.tsx
index aecdcf5..cd0253e 100644
--- a/web/src/app/settings/tabs/general-tab.tsx
+++ b/web/src/app/settings/tabs/general-tab.tsx
@@ -42,6 +42,7 @@ const generalFormSchema = z.object({
   // Others
   enableBackgroundInvestigation: z.boolean(),
   enableDeepThinking: z.boolean(),
+  enableWebSearch: z.boolean(),
   reportStyle: z.enum(["academic", "popular_science", "news", "social_media","strategic_investment"]),
 });
 
@@ -126,6 +127,29 @@ export const GeneralTab: Tab = ({
                 </FormItem>
               )}
             />
+            <FormField
+              control={form.control}
+              name="enableWebSearch"
+              render={({ field }) => (
+                <FormItem>
+                  <FormControl>
+                    <div className="flex items-center gap-2">
+                      <Switch
+                        id="enableWebSearch"
+                        checked={field.value}
+                        onCheckedChange={field.onChange}
+                      />
+                      <Label className="text-sm" htmlFor="enableWebSearch">
+                        {t("enableWebSearch")}
+                      </Label>
+                    </div>
+                  </FormControl>
+                  <FormDescription>
+                    {t("enableWebSearchDescription")}
+                  </FormDescription>
+                </FormItem>
+              )}
+            />
             {form.watch("enableClarification") && (
               <FormField
                 control={form.control}
diff --git a/web/src/core/api/chat.ts b/web/src/core/api/chat.ts
index 2432d4a..bb8e533 100644
--- a/web/src/core/api/chat.ts
+++ b/web/src/core/api/chat.ts
@@ -51,6 +51,7 @@ export async function* chatStream(
     interrupt_feedback?: string;
     enable_deep_thinking?: boolean;
     enable_background_investigation: boolean;
+    enable_web_search?: boolean;
     report_style?: "academic" | "popular_science" | "news" | "social_media" | "strategic_investment";
     mcp_settings?: {
       servers: Record<
diff --git a/web/src/core/store/settings-store.ts b/web/src/core/store/settings-store.ts
index de59a8d..00c1784 100644
--- a/web/src/core/store/settings-store.ts
+++ b/web/src/core/store/settings-store.ts
@@ -14,6 +14,7 @@ const DEFAULT_SETTINGS: SettingsState = {
     maxClarificationRounds: 3,
     enableDeepThinking: false,
     enableBackgroundInvestigation: false,
+    enableWebSearch: true,
     maxPlanIterations: 1,
     maxStepNum: 3,
     maxSearchResults: 3,
@@ -31,6 +32,7 @@ export type SettingsState = {
     maxClarificationRounds: number;
     enableDeepThinking: boolean;
     enableBackgroundInvestigation: boolean;
+    enableWebSearch: boolean;
     maxPlanIterations: number;
     maxStepNum: number;
     maxSearchResults: number;
@@ -174,4 +176,14 @@ export function setEnableClarification(value: boolean) {
   }));
   saveSettings();
 }
+
+export function setEnableWebSearch(value: boolean) {
+  useSettingsStore.setState((state) => ({
+    general: {
+      ...state.general,
+      enableWebSearch: value,
+    },
+  }));
+  saveSettings();
+}
 loadSettings();
diff --git a/web/src/core/store/store.ts b/web/src/core/store/store.ts
index ea87a6f..79167fe 100644
--- a/web/src/core/store/store.ts
+++ b/web/src/core/store/store.ts
@@ -115,6 +115,7 @@ export async function sendMessage(
       enable_deep_thinking: settings.enableDeepThinking ?? false,
       enable_background_investigation:
         settings.enableBackgroundInvestigation ?? true,
+      enable_web_search: settings.enableWebSearch ?? true,
       max_plan_iterations: settings.maxPlanIterations,
       max_step_num: settings.maxStepNum,
       max_search_results: settings.maxSearchResults,