The invention discloses a miniature circuit breaker breaking and closing mechanism capable of spirally controlling a speed. The miniature circuit breaker breaking and closing mechanism comprises a boxbody, an air switch, a cover plate, a knife switch and a speed control switch, wherein a front surface of the box body is hinged and connected with the cover plate, the air switch is arranged in thebox body, the knife switch is arranged on the air switch and is movably connected with the speed control switch, grooves are formed in a left side and a right side of the knife switch, the speed control switch comprises a sliding frame, a speed control rotation rod, a guide sleeve and a handle, the guide sleeve is connected with an outer side of the air switch and is arranged at a part below the knife switch, the speed control rotation rod penetrates through the guide sleeve and is in threaded connection with the guide sleeve, and the sliding frame is in a square shape. The miniature circuit breaker breaking and closing mechanism has the beneficial effects that a gate is moved by a self-locking effect of threaded connection, the moving speed is ensured, impact caused by automatic pop-out of the gate is prevented, the air switch is protected, the speed control rotation rod is controlled and loosen by combination and expansion of four threaded blocks, the control of the gate can be automatically loosen during trip, so that the circuit automatically trips and is protected.