Releasing mechanism for expansion drilling liner hanger and well cementation and completion pipe string

The utility model provides a releasing mechanism for an expansion drilling liner hanger and a well cementation and completion pipe string. The releasing mechanism comprises a first connector connected with a feeding pipe column, and the lower end of the first connector is provided with a plurality of joint teeth arranged at intervals in the circumferential direction; the second connector is connected with the tie-back barrel, a plurality of joint grooves which are arranged at intervals in the circumferential direction are formed in the upper end of the second connector, the joint grooves correspond to the joint teeth so as to be used for receiving the joint teeth, and the joint teeth and the joint grooves are matched so that torsion of the feeding pipe column can be transmitted to the tie-back barrel; and the clamping assembly is constructed to connect the first joint and the second joint together through clamping fit, and can separate the first joint from the second joint during releasing. 本实用新型提供了一种用于膨胀尾管悬挂