Abstract: In order to study the influence of termination compartment on explosion pressure of flameproof motor, the methane explosion test on YBF3-225M-2 (660/1140) flameproof three-phase asynchronous motor for fan was carried out by using the explosion proof test system. The results show that when the motor is rotating and ignition source is in the front cover, the explosion pressure at termination compartment is the largest, 0.432 MPa, and the rise time is 50 ms. Therefore, it is suggested that extra pressure measuring points should be set in the termination compartment when explosion pressure on the flameproof motor with termination compartment is measured.