Insulator defects can lead to insulation performance degradation and structural damage, affecting the regular operation of the power transmission and transformation system. It is important to Detect anomalies promptly, which can help prevent such accidents to the greatest extent possible. Temperature is one of the key indicators of the condition of insulators, and infrared thermal imaging technology is widely applied, which can detect latent defects in insulators. One of the critical parameters for infrared temperature measurement is target distance. However, infrared cameras cannot set distance parameters for different targets within an image, which presents challenges for inspecting multiple insulator strings based on one image. This paper proposes a multi-distance parameter temperature correction method based on monocular distance measurement algorithms to solve the problem. First, this paper uses a monocular distance measurement model to get the distance automatically. Then, this paper proposes a temperature-distance correction method to correct the temperature. Finally, re-image with the corrected temperature. The test results show that the average temperature correction is 0.6K, indicating that the correction is non-negligible.