Zero-value insulator infrared detection method is widely used with the characteristics of precision, efficiency and safety, but its measurement results are easily affected by the relative humidity and pollution degree of the environment. The coupling model of electric-thermal-flow field of polluted insulator string is established, and the influence of zero value insulator position, environmental relative humidity and pollution degree on the temperature distribution of insulator string is analyzed. Then, an infrared detection method of zero value insulator based on adjacent temperature rise difference is proposed and verified by experiments. The results show that the continuous saddle temperature distribution of insulator stringcanbe destroyed because of zero value. The farther the insulator is from the rotating center shaft, the lower the temperature rise is, and vice versa. The maximum temperature rise appears at the connection between the iron foot and the lower surface. With the increase of environmental relative humidity and pollution degree, the overall temperature rise of insulator string gradually increases, and the temperature rise difference between zero value insulator and normal insulator gradually increases. The experimental results show that it is feasible and effective for the zero-value insulator detection in field with this method.