The invention relates to a crusher, in particular to a crusher with a transmission belt breakage detection function. The crusher comprises a main machine and a driving device, wherein the driving device comprises a motor, a motor groove wheel, transmission belts, a transmission shaft groove wheel and a transmission shaft, the motor drives the motor groove wheel to rotate, the motor groove wheel drives the transmission shaft groove wheel to rotate through the transmission belts, an expansion sleeve is arranged between the transmission shaft groove wheel and the transmission shaft, wherein the transmission shaft groove wheel and the transmission shaft run at the same rotating speed, the transmission shaft drives the main machine to run, a conveyor belt breakage detection device is arranged above the transmission belt, and the conveyor belt breakage detection device is a capacitive proximity switch. The transmission belt breakage detection device is arranged on the crusher, when any transmission belt of the crusher is broken, the detection device can generate electric signal abnormity, the abnormity is fed back to a control system, and therefore the crusher is shut down and gives an alarm, and the crusher is prevented from being in an abnormal working state.