Controllable segmented pressure relief device and pressure relief method in freezing method construction

The invention discloses a controllable segmented pressure relief device in freezing method construction. The controllable segmented pressure relief device comprises a combined pressure relief pipe, a drill bit and an operation wrench. Each combined pressure relief pipe comprises a pressure relief floral pipe arranged outside and an inner pipe tightly attached to the inner wall of the pressure relief floral pipe, and the inner pipe can rotate in the pressure relief floral pipe. A plurality of outer mud leakage holes are formed in the peripheral wall of the pressure relief floral tube at intervals, inner mud leakage holes in one-to-one correspondence with the outer mud leakage holes are formed in the peripheral wall of the inner tube, and an inner wrenching plate is fixedly arranged on the inner wall of the inner tube; the device is ingenious in structure, practical in function and easy and convenient to operate; according to the pressure relief method disclosed by the invention, the inner barrel of the combine