diff --git a/backend/ruoyi-modules/ruoyi-aihr/src/main/java/org/dromara/aihr/agent/AihrAgentOrchestrator.java b/backend/ruoyi-modules/ruoyi-aihr/src/main/java/org/dromara/aihr/agent/AihrAgentOrchestrator.java
index 79fd13d3..186f1e7e 100644
--- a/backend/ruoyi-modules/ruoyi-aihr/src/main/java/org/dromara/aihr/agent/AihrAgentOrchestrator.java
+++ b/backend/ruoyi-modules/ruoyi-aihr/src/main/java/org/dromara/aihr/agent/AihrAgentOrchestrator.java
@@ -177,6 +177,9 @@ public class AihrAgentOrchestrator {
         if (request == null || request.question() == null || request.question().isBlank()) {
             throw new ServiceException("问题不能为空", 400);
         }
+        if (request.question().trim().length() > 1000) {
+            throw new ServiceException("问题长度必须为 1-1000 字", 400);
+        }
     }
 
     private static boolean needsKnowledge(String question) {
diff --git a/backend/ruoyi-modules/ruoyi-aihr/src/test/java/org/dromara/aihr/agent/AihrAgentOrchestratorTest.java b/backend/ruoyi-modules/ruoyi-aihr/src/test/java/org/dromara/aihr/agent/AihrAgentOrchestratorTest.java
index 630fceda..28761963 100644
--- a/backend/ruoyi-modules/ruoyi-aihr/src/test/java/org/dromara/aihr/agent/AihrAgentOrchestratorTest.java
+++ b/backend/ruoyi-modules/ruoyi-aihr/src/test/java/org/dromara/aihr/agent/AihrAgentOrchestratorTest.java
@@ -21,6 +21,7 @@ import static org.dromara.aihr.agent.AihrAgentDto.Intent.KNOWLEDGE_QA;
 import static org.dromara.aihr.agent.AihrAgentDto.Intent.LIVE_MY_WORK;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 @Tag("dev")
@@ -104,6 +105,20 @@ class AihrAgentOrchestratorTest {
         assertEquals("opaque-draft", result.actionDraft().draftId());
     }
 
+    @Test
+    void questionLongerThanKnowledgeBoundaryIsRejectedBeforePlanning() {
+        var query = new CapturingQueryService(response("unused", null, false));
+
+        var error = assertThrows(
+            org.dromara.common.core.exception.ServiceException.class,
+            () -> orchestrator(query).handle(request("A".repeat(1001)))
+        );
+
+        assertEquals(400, error.getCode());
+        assertTrue(error.getMessage().contains("1-1000"));
+        assertEquals(0, query.callCount);
+    }
+
     private static AihrAgentOrchestrator orchestrator(CapturingQueryService query) {
         return orchestrator(query, null);
     }