In this case, he should first try to communicate with his wife to let her understand his mother's personality and lifestyle, as well as his concern and support for her. He told her that he understood her point of view, but at the same time, he hoped that she could respect her mother and not impose her own ideas on others. If communication fails, you can consider expressing your feelings to your wife, telling her that you care about her feelings, but at the same time, you also hope that she can understand your position and not complain too much about your mother-in-law. In addition, you can consider asking your wife for help from other family members, such as your father, siblings, etc., so that they can communicate with your wife to find a solution to the problem. If your wife's complaints have become a norm and affect your family life and relationships, you can consider seeking professional psychological consultation to help you better deal with this complicated interpersonal relationship problem.