Gob-side entry retaining pressure relief zone observation method

The invention provides a gob-side entry retaining pressure relief zone observation method, which comprises the following steps: transmitting waves to an unpunched solid coal side and a roadway roof by using a wave transceiver, receiving the waves, analyzing the state of the waves to obtain an approximate range of a pressure relief zone, drilling holes in the coal side and the roadway roof according to the range of the pressure relief zone, and observing the pressure relief zone. A detachable device carrying a wave emission receiver and a high-definition camera is regularly and continuously pushed into a drill hole through a hollow push rod, the wave emission receiver emits waves and receives the waves, the high-definition camera monitors the fracture condition in the drill hole, the wave emission receiver and the high-definition camera store received data in a data collector located outside the drill hole, and the data collector is used for collecting the fracture condition in the drill hole. The fracture con