Anchoring and releasing device for oil and gas well

The invention discloses an anchoring release device for an oil-gas well. The problem that an existing anchoring releasing device and a supporting anchor cannot be released after being anchored is mainly solved. The bottom of the upper connector (1) is connected with a piston, a hydraulic cylinder is arranged outside the piston, the bottom of the hydraulic cylinder is connected with a lower connector (13), the bottom of the piston is connected with a pull rod (14), and a longitudinal center channel (2) is arranged in the piston and the upper connector (1). The piston comprises at least two piston single bodies which are connected up and down, the hydraulic cylinder comprises at least two hydraulic cylinder single bodies which are connected up and down, the first piston (5) divides the interior of the first hydraulic cylinder (4) into a first air chamber (3) and a first hydraulic chamber (6), and a first water hole (7) is formed in the position, corresponding to the first hydraulic chamber (6), of the first pis