The built-in slip drilling liner hanger comprises a lifting connector, a
coupling, a releasing
shear pin, a positioning sliding sleeve, an inner tube and a hanging body, external threads and internal threads are arranged at the lower end of the lifting connector, and the lower end of the lifting connector is connected with the
coupling through the external threads and connected with the inner tube through the internal threads; the lower end of the
coupling is connected with an upper clamp spring sleeve, a positioning sliding sleeve is sleeved in the coupling and is connected with the coupling through a releasing
shear pin, and the outer side of the coupling is connected with a suspension body; the lower end of the suspension body is connected with a nipple; the lower end of the inner
pipe is connected with a fixing nut, the inner
pipe is sleeved with a
hydraulic cylinder, the lower end of the
hydraulic cylinder is sequentially connected with a
piston and a centralizing sleeve, the
piston is sleeved with a slip sliding sleeve, and the lower end of the slip sliding sleeve is connected with a lower clamp spring sleeve. The suspension body is provided with the built-in slip, the slip is located in the groove of the suspension body, the slip cannot be collided by a tubular column in the descending process, and the problem that the small annulus of the horizontal well is difficult to descend is effectively solved.