How do i deal with my boyfriend's jealous ex wife?

Leave him. He has unfinished business with his wife. When he has completed his business, when the divorce is final, the ets are divided, the emotions have cooled, and he is having no contact with her other than amicable discussions about their mutual children, THEN it's OK to get involved with him. This is too early. Back out and let them deal with each other until they're done.