There are many factors affecting the accuracy of infrared temperature imaging technology. Especially in the complex environment of the experimental field, sometimes it is difficult to reach the expected index. In order to effectively improve the measurement accuracy of portable infrared thermal imager in the field, the main influencing factors of the field temperature measurement are sorted and summarized by the infrared temperature measurement theoretical model, and the influence factors are statistically analyzed by using the measured data in the field in the paper. In addition, the corresponding correction method is proposed. The results show that the standard deviation is reduced from 0.89 K to 0.3 K after the correction, which effectively improves the temperature measurement accuracy.