The invention discloses a method for carrying out a motive seal thermal failure test on a subjected sealing piece assembled in a transmission device. The method comprises a first step of setting parameters of test pressure, medium temperature, test revolving speed and test time needed by the subjected sealing piece motive seal thermal failure test, a second step of starting to heat the transmission device according to the set medium temperature, a third step of judging when the medium temperature in the transmission device reaches the set medium temperature by utilizing of a signal transmitted by a microsensor, providing pressure for the transmission device provided with the subjected sealing piece until oil pressure in the transmission device reaches the set test pressure and starting a motor to enable the test revolving speed of the transmission device to reach the set test revolving speed, and a fourth step of keeping the medium temperature, the test pressure and the test revolving speed unchanged until the set test time is reached, and recording test data related to temperature rising state, time, pressure and revolving speed about the subjected sealing piece before the set test time is reached.