A double-layered drainage tube (1), composed of an inner layer (11) and an outer layer (12) closely attached to each other, wherein the inner layer (11) is made of a hydrophobic material, and the outer layer (12) is made of a human biocompatible material. It can be ensured that liquids are not linked to an inner wall, thereby preventing bile adhesion from causing drainage tube clogging, and an outer wall thereof is soft and elastic and has a smooth surface, and has a good compatibility with body tissues without causing inflammation. Moreover, in the case where there is no middle layer of a stainless steel wire, the diameter and cost of an outer tube are reduced and the insertion difficulty is reduced, and the inner diameter of the drainage tube (1) is increased, and the effective drainage cross-sectional area of the drainage tube is increased.
