回复：H1B明年秋才到期。可是现在的雇主（学校）正加急办一个3个月就到期的H1B给我。

1。要是这个3个月的 part-time H1B批准了，我是不是就得3个月内一定要找到下家呀？原来的H1B是不是就自动作废呀?

-Why did they file such partime H1 for you again? Is this part-time H1 a new one or just H1 amendment? If your employer does not withdraw the old full-time H1, your full-time H1 is still valid as long as your employer continue to hire you at full time level and the part time H1 will not affect anyhting. However, USCIS may feels confused because it is very unusual for your employer to file two H1 petitions for you at the same period of time. So, the critical thing is to make sure whether your employer will withdraw your full-time H1 or not. If thye will not do that and will hire you continually, you will be fine.

2。要是这个3个月的 part-time H1B只批准了一半，发一张I-797B给我，没有I-94，我是不是就得回国拿签证啊？我可不可以用回原来的H1B呢？

-Depends on whether the full-time H1 was withdrawn or not. If withdrawn, you have to ge the h1 visa in this case. See above answer.