Separating brake of high pressure vacuum circuit breaker spring -operated mechanism is with two oily buffer structure, the separating brake buffer who has overcome current high voltage circuit breakerspring -operated mechanism adopts an oil bumper, the separating brake characteristic can not be adjusted, cause the separating brake to cross the problem that cushions or owe the buffering, nontunable oil bumper is installed to the characteristic in a separating brake spring protection section of thick bamboo, install adjustable oil bumper on the mount, the upper boom of nontunable oil bumper andthe first turning arm fixed connection who rotates the turning arm, install the gyro wheel on the second turning arm that rotates the turning arm, gyro wheel and adjustable oil bumper striking when the separating brake, reduce oening speed in the twinkling of an eye, the beneficial effects are that simple structure, the convenience is maintained and is easily adjusted the separating brake characteristic, the cushioning effect is exert with nontunable oil bumper simultaneously to the adjustable oil bumper during separating brake, the processing degree of difficulty that adopts single oil bumper has been reduced, the product percent of pass has been improved, high -pressure vacuum circuit breaker's separating brake characteristic has been improved, the batch production who is fit for high -pressure vacuum circuit breaker.