How to avoid my advisor as a reference? I had a bad relationship with my advisor. He told me evidently that he won’t write the recommendation letter for me in the future.

Of course, I will not put him in my reference list in my future career. But I don’t know if the future employer will contact him or question my working performance or attitude? I feel very bad about this. Can you guys give me some suggestions?
There are two issues in my mind. The first is not having the post doc supervisor as a reference. As you get further along in your career, you will have to leave someone that knows you well off your list of references. If you can develop a strong enough network that you have 3-5 people who know you and your work well and are willing to write you strong letter, then the absence of your post doc supervisor will not be seen s odd.

The second issue is more problematic and that is if your post doc advisor is contacted informally, he may actively or inactively sabotage you. In order to get around this, you need to repair the relationship, such that it is not a problem. As a first step, make sure that he is really unwilling to be a reference. If that is the case, then make it clear that you will not use him as a reference. Ask him if he is willing to tactfully deflect informal enquires. If he is, and you believe him, that you do not have much to worry about. If not, consider having one of your letter writers address the issues you have with you post doc supervisor.

Having a reference point out bad things is always dangerous in that it makes the hiring committee aware of something they might not find out about. The advantage is it is the only way to really get your side of the story told. It is worth talking to your other references about how to address the issue.