A biodegradable common bile duct stent and the method for preparing thereof are provided. The stent is made of biodegradable polymeric material with incorporation of X-ray opaque components. The stent adapts to the anatomical shape of the CBD or it can be sutured together with the wall of the bile duct. After placing the stent in the duct, it maintains its position and does not slip. The circular tube of the stent being suitably sized and having multiple ring-shaped protruding rims at the outer wall and/or with larynx structure, leakage and outflow of the bile are thereby prevented. It can be manufactured by a conventional injection-molding or an extrusion-blowing technique. In surgical operation on the bile duct, the stent can replace the T-tube which is conventionally used to support the duct and guide bile drainage. It can reduce the time required for surgical operation and treatment, reduce possible complications and can be degraded and eliminated as the incision heals and the CBD regains its normal functions.