diff --git a/proxy/src/main/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminService.java b/proxy/src/main/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminService.java
index f3c68eab5c4..d1ac5e0d07c 100644
--- a/proxy/src/main/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminService.java
+++ b/proxy/src/main/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminService.java
@@ -49,8 +49,12 @@ public boolean topicExist(String topic) {
         try {
             topicRouteData = this.getTopicRouteDataDirectlyFromNameServer(topic);
             topicExist = topicRouteData != null;
-        } catch (Throwable e) {
-            topicExist = false;
+        } catch (Exception e) {
+            if (TopicRouteHelper.isTopicNotExistError(e)) {
+                topicExist = false;
+            } else {
+                throw new IllegalStateException("get topic route for topic='" + topic + "' failed", e);
+            }
         }
 
         return topicExist;
diff --git a/proxy/src/test/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminServiceTest.java b/proxy/src/test/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminServiceTest.java
index cdfc7f7fc23..4996b75a6b8 100644
--- a/proxy/src/test/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminServiceTest.java
+++ b/proxy/src/test/java/org/apache/rocketmq/proxy/service/admin/DefaultAdminServiceTest.java
@@ -27,6 +27,7 @@
 import org.apache.rocketmq.remoting.protocol.route.TopicRouteData;
 import org.apache.rocketmq.client.impl.mqclient.MQClientAPIExt;
 import org.apache.rocketmq.client.impl.mqclient.MQClientAPIFactory;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -35,6 +36,7 @@
 import org.mockito.junit.MockitoJUnitRunner;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.anyString;
@@ -87,6 +89,27 @@ public void testCreateTopic() throws Exception {
         assertEquals(8, topicConfigArgumentCaptor.getValue().getReadQueueNums());
     }
 
+    @Test
+    public void testTopicExistReturnsFalseForNotFound() throws Exception {
+        when(mqClientAPIExt.getTopicRouteInfoFromNameServer(eq("missingTopic"), anyLong()))
+            .thenThrow(new MQClientException(ResponseCode.TOPIC_NOT_EXIST, "topic not exist"));
+
+        assertFalse(defaultAdminService.topicExist("missingTopic"));
+    }
+
+    @Test
+    public void testTopicExistThrowsForUnexpectedRouteLookupFailure() throws Exception {
+        MQClientException cause = new MQClientException(ResponseCode.SYSTEM_ERROR, "namesrv unavailable");
+        when(mqClientAPIExt.getTopicRouteInfoFromNameServer(eq("brokenTopic"), anyLong()))
+            .thenThrow(cause);
+
+        IllegalStateException exception = Assert.assertThrows(IllegalStateException.class,
+            () -> defaultAdminService.topicExist("brokenTopic"));
+
+        assertEquals("get topic route for topic='brokenTopic' failed", exception.getMessage());
+        assertEquals(cause, exception.getCause());
+    }
+
     private TopicRouteData createTopicRouteData(int brokerNum) {
         TopicRouteData topicRouteData = new TopicRouteData();
         for (int i = 0; i < brokerNum; i++) {
@@ -100,4 +123,4 @@ private TopicRouteData createTopicRouteData(int brokerNum) {
         }
         return topicRouteData;
     }
-}
\ No newline at end of file
+}