The invention discloses a motor protector. The motor protector comprises a single chip microcomputer control unit and a display screen which is electrically connected with the single chip microcomputer control unit, wherein the single chip microcomputer control unit is connected with a current transformer, a voltage transformer, a Hall sensor, a temperature sensor, a voice alarm module, a wireless transmission module, a lightning protection module, an air switch, an electric leakage protector, an automatic transformer, a magnetic field detection coil and a thermal relay at the same time. The motor protector is reasonable in design, capable of effectively protecting a three-phase motor by detecting the voltage, current, temperature and bearing position information, and high in precision, reliable in operation, and high in stability; various lines of motor operating parameters can be displayed on the display screen, so that an operator can analyze reasons; in addition, the motor operating parameters can be fed back in a remote manner through the wireless transmission module, so that the motor protector can be controlled more conveniently; and moreover, the operating voltages at the two ends of the motor can be automatically regulated through the automatic transformer to prevent undervoltage and overvoltage, thereby prolonging the service life of the motor.