Abstract: Aiming at the problems of inconvenient installation and short maintenance interval of the mechanical engine overload protection device on the small branch crusher,the electronic control engine overload protection scheme is proposed.The MCU obtains the real-time engine speed through rectifier circuit and voltage comparison circuit.When the real-time engine speed is less than the preset engine overload speed,the MCU separates the clutch of the branch feeding device,the crushing device continues to crush the branch which has been fed.After the engine speed is restored,the MCU makes the branch feeding device run again,so as to realize the electronic control engine overload protection device.The test shows that the speed of the engine collected by the device is accurate,and the overload protection function of the branch crusher engine is realized without relying on additional sensors,which effectively solves the problems of inconvenient installation and debugging and short maintenance interval of the overload protection device of the small branch crusher.