Ascariasis is mainly caused by the ingestion of infective ascaris eggs. The eggs hatch in the duodenum and the output larvae burrow into the wall of the small intestine, then migrate through the blood circulation to the heart and lungs, from which they travel up the bronchi to the oropharynx and are swallowed back into the small intestine, where they develop into adult worms. It takes about 2 months to complete the life history, and the life span of adult worms is about 6-12 months. For the prevention and treatment of ascariasis, comprehensive measures should be taken, including several aspects such as investigating and treating patients and worm carriers, handling feces, managing water sources and preventing infection. It is necessary to strengthen publicity and education, popularize hygiene knowledge, pay attention to diet and personal hygiene, wash hands before meals and after defecation, do not eat raw unwashed vegetables and fruits, and do not drink raw water.