diff --git a/be/src/exprs/hybrid_set.h b/be/src/exprs/hybrid_set.h
index 03cde80c24..c45167a83b 100644
--- a/be/src/exprs/hybrid_set.h
+++ b/be/src/exprs/hybrid_set.h
@@ -421,7 +421,7 @@ public:
     void _insert_fixed_len_string(const auto& col, const uint8_t* __restrict nullmap, size_t start,
                                   size_t end) {
         for (size_t i = start; i < end; i++) {
-            if (nullmap != nullptr || !nullmap[i]) {
+            if (nullmap == nullptr || !nullmap[i]) {
                 _set.insert(col.get_data_at(i).to_string());
             } else {
                 _contains_null = true;
@@ -583,7 +583,7 @@ public:
     void _insert_fixed_len_string(const auto& col, const uint8_t* __restrict nullmap, size_t start,
                                   size_t end) {
         for (size_t i = start; i < end; i++) {
-            if (nullmap != nullptr || !nullmap[i]) {
+            if (nullmap == nullptr || !nullmap[i]) {
                 _set.insert(col.get_data_at(i));
             } else {
                 _contains_null = true;
diff --git a/regression-test/data/query_p0/join/no_null_str_rf/no_null_str_rf.out b/regression-test/data/query_p0/join/no_null_str_rf/no_null_str_rf.out
new file mode 100644
index 0000000000..ebb4260eeb
--- /dev/null
+++ b/regression-test/data/query_p0/join/no_null_str_rf/no_null_str_rf.out
@@ -0,0 +1,4 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !test --
+4
+
diff --git a/regression-test/suites/query_p0/join/no_null_str_rf/no_null_str_rf.groovy b/regression-test/suites/query_p0/join/no_null_str_rf/no_null_str_rf.groovy
new file mode 100644
index 0000000000..0b13db03a2
--- /dev/null
+++ b/regression-test/suites/query_p0/join/no_null_str_rf/no_null_str_rf.groovy
@@ -0,0 +1,58 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+suite("no_null_str_rf") {
+    sql """ DROP TABLE IF EXISTS d_table; """
+    sql """ DROP TABLE IF EXISTS dd_table; """
+    sql """
+            create table d_table(
+                k1 int null,
+                k2 int not null,
+                k3 bigint null,
+                k4 varchar(100) not null
+            )
+            duplicate key (k1,k2,k3)
+            distributed BY hash(k1) buckets 3
+            properties("replication_num" = "1");
+        """
+
+    sql "insert into d_table select 1,1,1,'a';"
+    sql "insert into d_table select 1,1,1,'b';"
+    sql "insert into d_table select 1,1,1,'a';"
+    sql "insert into d_table select 1,1,1,'b';"
+    sql "insert into d_table select 1,1,1,'a';"
+    sql "insert into d_table select 1,1,1,'b';"
+    sql "insert into d_table select 1,1,1,'a';"
+    sql "insert into d_table select 1,1,1,'b';"
+
+    sql """
+            create table dd_table(
+                k1 int null,
+                k2 int not null,
+                k3 bigint null,
+                k4 varchar(100) not null
+            )
+            duplicate key (k1,k2,k3)
+            distributed BY hash(k1) buckets 3
+            properties("replication_num" = "1");
+        """
+
+    sql "insert into dd_table select 1,1,1,'a';"
+    sql "insert into dd_table select 1,1,1,'c';"
+
+    qt_test """select count(1) from d_table,dd_table where d_table.k4=dd_table.k4 and d_table.k1=1 and dd_table.k1=1;"""
+}