Pinworm eggs survive for a long time outside the body, and normal pinworm eggs can be transformed into infectious eggs in six hours, so many patients are repeatedly self-infected. Pinworms are mainly parasitic in the end of the ileum, cecum, and colon. After the mating of the male and female worms, the male worms die quickly, and the female worms with a large number of eggs crawl to the colon and the skin around the outside of the anus at night to lay eggs. Because of itching around the anus, many children have the habit of scratching the anus, and these eggs are swallowed through the infected fingers and food, and gradually move to the ileocecal region in the small intestine to develop into adult worms. The main prevention of recurrent pinworms is to develop good hygiene habits, wash hands regularly, cut nails regularly, not to suck fingers, and try to wear crotch pants for the affected children to avoid scratching and scratching the anus at night and to keep the anus clean and dry at all times.