Cat ear mites need to be exterminated first, and selamectin can be applied once every two weeks. Afterwards, you can use physiological saline or ear cleaning solution to clean the ears once a day. It is recommended to use cotton swabs to clean the ears until there is no obvious earwax. After that, apply some ear ointment, such as Erfuling, etc. It is recommended to wear an Elizabethan ring to prevent the cat from scratching. Moreover, the ointment needs to be applied half an hour after cleaning, about 3 times a day, and keep it for a week. Go to the hospital for regular check-ups.