After discovering fleas on your cat, give the cat a bath, clean the home environment and cat supplies, and then deworm the cat externally and internally. Let the cat spend more time in the sun and observe it for a period of time to see if there are still fleas on it. If there are fleas, keep the room clean and ventilated during this period. After that, the cat will be dewormed regularly every month to prevent the fleas from recurring.