The utility model provides a motor torque rotating speed measuring device, comprising a sensor, a low frequency signal phase difference measuring module, a one-chip microcomputer module, a digital display module, a keyboard module, an acousto-optic alarm module and a power supply module. The output 2 signal of the sensor is processed by the low frequency signal phase difference measuring module and then is sent to the one-chip microcomputer module for further processing. The actual measurement data of motor torque and rotating speed is sent to the digital display module for conducting real-time data display. When the torque and rotating speed of the detected motor exceed the set alarm threshold, the one-chip microcomputer outputs alarm signal to the acousto-optic alarm module, sound and light flashing alarm is conducted by the acousto-optic alarm module. The motor torque rotating speed measuring device is advantageous in that the motor torque rotating speed measuring device is composed of a digital circuit with a ZJ type sensor and a one-chip microcomputer being the core, and thereby cost is low, applicability is strong, measuring precision is high, and digitalized display is visual and convenient; when the motor to be detected is overloaded or overspeed, the acousto-optic alarm will be sent instantly, and motor damage can be effectively prevented.