Adult biliary ascaris is suitable for endoscopic treatment 【Method】 1.Insert the duodenoscope into the duodenum and find the papilla, if the ascaris has been embedded, it can be removed directly. 2.If the roundworm has entered into the bile duct, decide whether to perform EST according to the situation. 3.Insert the lithotripsy basket into the bile duct for blind extraction, or inject the contrast agent, and retrieve the basket under the guidance of X-ray, the general success rate is above 95%. 4.If the retrieval fails, 100ml of oxygen will be injected from the catheter, and the roundworms in the bile duct can be discharged within 24 hours. 5.Appropriate antibiotics are applied after the operation, and intestinal expulsion treatment is given at the same time.