In order to solve the problems of accuracy and poor reliability of the belt conveyor temperature detector in coal mines, this paper proposes a design scheme for the intrinsically safe infrared thermometer of the belt conveyor. The hardware is designed using MLX90614 infrared sensor and STM32F103C8T6 processor; on Keil 5.14 development platform, the software is designed in C language. And conducted experiments, the results show that the infrared thermometer has a temperature range of .20℃-380℃, high resolution, accurate temperature measurement, temperature measurement accuracy of ±0.5℃, non-contact measurement, not easy to damage, high reliability, can be widely used in coal, mines, ports, electric power, metallurgy, chemical industry and other fields.