diff --git a/fe/fe-core/src/main/java/org/apache/doris/catalog/PartitionKey.java b/fe/fe-core/src/main/java/org/apache/doris/catalog/PartitionKey.java
index 3fd0732a91ebfd..c5cc70e3a9511d 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/catalog/PartitionKey.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/catalog/PartitionKey.java
@@ -137,11 +137,11 @@ public static int compareLiteralExpr(LiteralExpr key1, LiteralExpr key2) {
             try {
                 LiteralExpr newKey = key1;
                 if (key1.getType() != destType) {
-                    newKey = (LiteralExpr) key1.castTo(destType);
+                    newKey = (LiteralExpr) key1.castTo(destType).getResultValue();
                 }
                 LiteralExpr newOtherKey = key2;
                 if (key2.getType() != destType) {
-                    newOtherKey = (LiteralExpr) key2.castTo(destType);
+                    newOtherKey = (LiteralExpr) key2.castTo(destType).getResultValue();
                 }
                 ret = newKey.compareLiteral(newOtherKey);
             } catch (AnalysisException e) {