回複：緊急求助皮匠、知名度等大俠, 在H1B生效前, 我是否可以出入境?

When you leave during H-1 pending, the petition may be invalidated.
http://blog.wenxuecity.com/blogview.php?date=200709&postID=16851#EosCos

After H-1 has been approved, I think it is not affected by your travel prior to its effective date. However, you may need to be admitted in H-1.