The invention relates to an adjustable pressure detection steel pipe disengaging device and a working method thereof. The adjustable pressure detection steel pipe disengaging device comprises a shelland a middle beam fixing plate, the middle beam fixing plate is arranged in the shell, a fixing frame and a telescopic rod are fixedly arranged on the middle beam fixing plate, the telescopic rod is arranged on the fixing frame and is driven by a push-pull motor, an electromagnet is connected at the lower end of the telescopic rod, a speed reducer and a pushing screw are fixedly arranged on an upper fixing beam of the shell, the speed reducer drives the pushing screw to rotate, a pushing threaded sleeve is connected on the pushing screw in a sleeved manner to form a lead screw nut pair and fixed on a pushing frame, a knocking spring is arranged between a pre-tightening pressure plate of the lower portion of the pushing frame and a knocking sucker positioned on a lower fixing beam of the shell, a knocking rod is arranged on the lower surface of the knocking sucker and extends out of the lower fixing beam of the shell, and the telescopic rod drives the electromagnet to vertically move between the pre-tightening pressure plate and the knocking sucker. The disengaging device is simple in structure and reasonable in design, and knocking information is highly accurately inspected.