diff --git a/src/hooks/useAlign.ts b/src/hooks/useAlign.ts
index c8a50991..db297856 100644
--- a/src/hooks/useAlign.ts
+++ b/src/hooks/useAlign.ts
@@ -698,13 +698,13 @@ export default function useAlign(
         popupMirrorRect.bottom - popupRect.y - (nextOffsetY + popupRect.height);
 
       if (scaleX === 1) {
-        nextOffsetX = Math.round(nextOffsetX);
-        offsetX4Right = Math.round(offsetX4Right);
+        nextOffsetX = Math.floor(nextOffsetX);
+        offsetX4Right = Math.floor(offsetX4Right);
       }
 
       if (scaleY === 1) {
-        nextOffsetY = Math.round(nextOffsetY);
-        offsetY4Bottom = Math.round(offsetY4Bottom);
+        nextOffsetY = Math.floor(nextOffsetY);
+        offsetY4Bottom = Math.floor(offsetY4Bottom);
       }
 
       const nextOffsetInfo = {
diff --git a/tests/align.test.tsx b/tests/align.test.tsx
index 858f312b..d4e7386b 100644
--- a/tests/align.test.tsx
+++ b/tests/align.test.tsx
@@ -272,7 +272,7 @@ describe('Trigger.Align', () => {
     });
   });
 
-  it('round when decimal precision', async () => {
+  it('floor when decimal precision', async () => {
     rectX = 22.6;
     rectY = 33.4;
     rectWidth = 33.7;
@@ -293,7 +293,7 @@ describe('Trigger.Align', () => {
     await awaitFakeTimer();
 
     expect(document.querySelector('.rc-trigger-popup')).toHaveStyle({
-      top: `56px`,
+      top: `55px`,
     });
   });