The utility model discloses an infrared human body sensor with communication link function of supplying power, including the drain pan, the rear of drain pan is provided with the epitheca, and the inside of drain pan is provided with the circuit board, the upper end surface of drain pan is close to front end department and is provided with the draw -in groove, and the front end surface movable mounting of drain pan has a control post, the inside of epitheca is close to the middle fixed mounting of department has the printing opacity mirror, and the front end surface of epitheca is close to thefixed mounting of upper end department and has a buckle, the below of buckle is provided with the fixed column. The utility model discloses a being provided with a series of structures and making this device in the use, the phenomenon that at first can effectually avoid installing the wiring error takes place, reduces the work load of staff when the installation wiring, secondly can improve fieldbus's communication speed, increases its transmission efficiency, and convenient to use person inspects the internal fault of this sensor, optimum usage process in addition.