The digital temperature sensor DS18B20 is used, and the sealant with high thermal conductivity is used to seal, which ensures the high sensitivity and small temperature delay of the temperature sensor. The temperature sensor supports "bus" interface (1-wire), and the temperature range is - 55 ℃ ° C～+125 ° C. From - 10 to + 85 ° Within the range of C, the accuracy is ± zero point five ° C。 The field temperature is directly transmitted in the digital mode of "bus", which greatly improves the anti-interference of the system. It is suitable for field temperature measurement in harsh environment.