In recent years, image fusion technology has been widely used in the power industry. Different types of image sensors are used to collect images of power equipment and transmission lines. Through the fusion of infrared and visible light images, intelligent inspection and fault analysis of power equipment and transmission lines can be realized. This article first briefly introduces common image fusion algorithms and fusion image evaluation standards. A multi-scale image fusion algorithm based on adaptive weighting is proposed, which uses the registered visible light and infrared images to perform multi-scale wavelet decomposition. According to the different image characteristics of high and low frequencies, the low frequency adopts the adaptive weighted fusion rule and the high frequency adopts the fusion rule with the largest absolute value. The fused wavelet coefficients are inversely transformed to obtain a new fused image. Subjective and objective evaluation and analysis of the fusion image confirm that the fusion algorithm solves the integrity problem of the image collected by a single image sensor, enhances the detailed information of the fusion image, and improves the confidence of the scene.