The invention provides a method for repairing deformation of the articulated part of a down hole shield machine. The method includes the following steps that (1) an articulated oil cylinder is removed; (2) a "T"-shaped steel plate is welded to a front shield/middle shield, and a base is welded to a tail shield; (3) a hydraulic jack is used for separating the middle shield and the tail shield to 35-45 cm; (4) the deformation part is measured, and subsidy calculation and burdening are conducted; next, compacting blocks are numbered and disassembled after numbered, and at the same time corresponding front rubber seal is removed; (5) subsidies are polished, and the front rubber seal and compacting blocks are reinstalled at the position where the front rubber seal is installed; and (6) the hydraulic jack is used for moving the distance between the middle shield and the tail shield back to 15-25 cm position, and the articulated cylinder is reinstalled; and finally, the middle shield and tail shield are in position by using the articulated cylinder. According to the method, the deformation position of the tail shield of a shield machine can be repaired directly in normal downhole assembly work, manpower, material resources and financial resources are saved, and the maintenance period is shortened.