I'm not familiar with that type of fish. I assume you mean cichlids?
Do you have enough hiding spaces for the female to avoid the male and to break up the lines of sight in the tank? More cover often reduces aggression as the male isn't constantly seeing and then attacking the female, and also it gives more spots for hiding so they aren't both trying to use / defend the same one. Making sure the tank is large enough is also important.
I have also heard of good luck with taping a mirror up against one side of the tank - if the male is busy defending his territory against the "intruding male," he can't be attacking the female at the same time. This is often only a shorter term fix (a few days or so) but that depends on the individual fish as well.
If he's actually doing damage to her, you may need to separate them at least temporarily - can be as easy as putting a divider in the tank to give her a break.