Is it permissible for a husband to severely beat his wife due to her jealousy over him and his bad treatment of her at home, knowing that he is a kung fu instructor and physically harms her?

The spouses are obligated to treat each other with kindness, and it is not permissible for the husband to beat his wife severely. If your husband does that, he is an oppressor and mistreats the marital relationship. The beating permitted in cases of disobedience (nushuz) is non-severe beating, based on the saying of the Prophet, peace and blessings be upon him: "If they do that, then beat them with a non-severe beating."

We advise you to treat your husband with kindness and explain to him that Islamic law does not permit severe beating, and that being good to one's wife is a righteous deed, based on the sayings of the Prophet, peace and blessings be upon him: "Treat women kindly," and "The best of you is the best to his family, and I am the best to my family." If that does not work, then some wise individuals should intervene to reconcile between you.