diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommand.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommand.java
index b686add882f76e..5daf756db96508 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommand.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommand.java
@@ -81,16 +81,17 @@ public ShowResultSet doRun(ConnectContext ctx, StmtExecutor executor) throws Exc
                 userIdent = ConnectContext.get().getCurrentUserIdentity();
             }
         }
+        boolean isSelf = userIdent != null && ConnectContext.get().getCurrentUserIdentity().equals(userIdent);
         Preconditions.checkState(isAll || userIdent != null);
-        UserIdentity self = ConnectContext.get().getCurrentUserIdentity();
-
         // if show all grants, or show other user's grants, need global GRANT priv.
-        if (isAll || !self.equals(userIdent)) {
+        if (isAll || !isSelf) {
             if (!Env.getCurrentEnv().getAccessManager().checkGlobalPriv(ConnectContext.get(), PrivPredicate.GRANT)) {
                 ErrorReport.reportAnalysisException(ErrorCode.ERR_SPECIFIC_ACCESS_DENIED_ERROR, "GRANT");
             }
         }
-        if (userIdent != null && !Env.getCurrentEnv().getAccessManager().getAuth().doesUserExist(userIdent)) {
+        // ldap user not exist in userManager, so should not check
+        if (userIdent != null && !isSelf && !Env.getCurrentEnv().getAccessManager().getAuth()
+                .doesUserExist(userIdent)) {
             throw new AnalysisException(String.format("User: %s does not exist", userIdent));
         }
         List<List<String>> infos = Env.getCurrentEnv().getAuth().getAuthInfo(userIdent);
diff --git a/fe/fe-core/src/test/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommandTest.java b/fe/fe-core/src/test/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommandTest.java
index 5699069b161d9b..ffcbcdb42863b1 100644
--- a/fe/fe-core/src/test/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommandTest.java
+++ b/fe/fe-core/src/test/java/org/apache/doris/nereids/trees/plans/commands/ShowGrantsCommandTest.java
@@ -86,4 +86,21 @@ void testDorun() throws Exception {
         int size = results.size();
         Assertions.assertEquals("'zzz'@'%'", results.get(size - 1).get(0));
     }
+
+    @Test
+    void testNonExistUser() {
+        ConnectContext ctx = ConnectContext.get();
+        UserIdentity nonExistUser = UserIdentity.createAnalyzedUserIdentWithIp("non_exist_user", "%");
+        Assertions.assertThrows(AnalysisException.class, () -> {
+            ShowGrantsCommand sg = new ShowGrantsCommand(nonExistUser, false);
+            sg.doRun(ctx, null);
+        });
+
+        ctx.setIsTempUser(true);
+        ctx.setCurrentUserIdentity(nonExistUser);
+        Assertions.assertDoesNotThrow(() -> {
+            ShowGrantsCommand sg = new ShowGrantsCommand(null, false);
+            sg.doRun(ctx, null);
+        });
+    }
 }