What can I do when my husband constantly threatens for divorce anytime we disagree or argue? I have told him many times how his empty threats upset me, should I take him seriously?

It seems like your husband uses the threat of divorce so that you can agree with whatever he says. It is possible that he is saying it out of anger, which develops into a habit. It is also possible that he is saying it to win the argument and that he knows you won't leave him. I am glad to hear that you are voicing your concerns to your husband. Did he change his behavior? If not, it is likely he thinks his behavior is unproblematic. He may also continue to use this tactic to keep you in this marriage. The most important question is whether you want to stay in this marriage. Is this behavior what you want in a husband? Do you think he is capable of change? Was he like this before, and if not, what do you think caused this change?