For the problem that temperature sensors of mine belt transport system can’t be inspected in real time and on site, design a based on Smith estimated compensation control for portable underground conveyer temperature sensor detection device. The working principle of the device is introduced in detail, the hardware design of thermostat, intrinsically safe power supply circuit and the drive system based on the Smith prediction control is expounded and the flow chart of main program software is given in this paper. The experimental result and field operation results show that the device has the characteristics of convenient carrying, accurate measurement, realtime and onsite detection and so on.