diff --git a/packages/fineui/src/core/utils/dom.js b/packages/fineui/src/core/utils/dom.js
index fbee6b287..1be70de14 100644
--- a/packages/fineui/src/core/utils/dom.js
+++ b/packages/fineui/src/core/utils/dom.js
@@ -744,10 +744,11 @@ export function getComboPosition(combo, popup, extraWidth, extraHeight, needAdap
     if (needAdaptHeight === true && popup.resetHeight) {
         const comboRect = combo.element[0].getBoundingClientRect();
         const relativeOffset = positionRelativeElement ? positionRelativeElement.getBoundingClientRect().top : 0;
-        if (position.top < comboRect.top) {
-            popup.resetHeight(Math.min(viewportBounds.height - position.top - relativeOffset, comboRect.top, maxHeight));
-        } else if (position.top >= comboRect.bottom) {
-            popup.resetHeight(Math.min(viewportBounds.height - position.top - relativeOffset, viewportBounds.height - comboRect.bottom, maxHeight));
+        const positionTop = position.top + relativeOffset;
+        if (positionTop < comboRect.top) {
+            popup.resetHeight(Math.min(viewportBounds.height - positionTop, comboRect.top, maxHeight));
+        } else if (positionTop >= comboRect.bottom) {
+            popup.resetHeight(Math.min(viewportBounds.height - positionTop, viewportBounds.height - comboRect.bottom, maxHeight));
         }
     }