diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssoc.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssoc.java
index 2080cfce93..3208654fa7 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssoc.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssoc.java
@@ -79,7 +79,7 @@ public class OuterJoinAssoc extends OneExplorationRuleFactory {
                                 .addAll(topJoin.getOtherJoinConjuncts()).build();
                         Set<Slot> notNullSlots = ExpressionUtils.inferNotNullSlots(on,
                                 ctx.cascadesContext);
-                        if (!conditionSlot.equals(notNullSlots)) {
+                        if (conditionSlot.isEmpty() || !conditionSlot.equals(notNullSlots)) {
                             return null;
                         }
                     }
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssocProject.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssocProject.java
index 512aec7bbc..5cd22058c0 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssocProject.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/exploration/join/OuterJoinAssocProject.java
@@ -80,7 +80,7 @@ public class OuterJoinAssocProject extends OneExplorationRuleFactory {
                                 .addAll(topJoin.getOtherJoinConjuncts()).build();
                         Set<Slot> notNullSlots = ExpressionUtils.inferNotNullSlots(on,
                                 ctx.cascadesContext);
-                        if (!conditionSlot.equals(notNullSlots)) {
+                        if (conditionSlot.isEmpty() || !conditionSlot.equals(notNullSlots)) {
                             return null;
                         }
                     }