Ascaris lumbricoides is mainly parasitized in the small intestine. Ascaris lumbricoides mainly parasitizes the small intestine and uses the semi-digested food in the small intestine as food to rob the host of a large amount of nutrients, and also damages the intestinal mucosa, leading to indigestion and nutrient absorption disorders, causing malnutrition. Patients often manifest digestive symptoms, such as loss of appetite, nausea, vomiting, abdominal pain, abdominal distension. In addition, roundworms have the habit of drilling holes into various ducts that open into the intestinal wall (e.g., bile ducts, pancreatic ducts, and appendix), and even into the liver, resulting in biliary ascariasis, ascaris intestinal obstruction, and hepatic ascariasis. If the above clinical symptoms occur, we should be alert to roundworm infection, and need to consult a doctor as soon as possible to complete the relevant examinations to confirm the diagnosis, and use anthelmintic drugs under the guidance of the doctor for treatment to avoid serious consequences.