This study proposes an infrared image enhancement method combined with single scale Retinex and guided image filtering to eliminate the problems of low image contrast, loss of detail information, and excessive enhancement in traditional infrared image enhancement algorithms. First, a structure extraction algorithm is used to obtain the incident and reflected components of the original image according to the Retinex algorithm. The platform histogram is used to enhance the contrast of the incident component. Then, the reflected component is decomposed into the base layer and detail layer by the weighted guided image filter based on variance and by performing contrast and detail enhancement operations on the images of the two components, respectively. Finally, the results of each level are fused according to the appropriate weight factors to obtain an enhanced infrared image. The experiments in this study show that the proposed method can improve the overall contrast of infrared images and highlight their detailed features more effectively than other enhancement algorithms. The information entropy and average gradient of the three groups of images after enhancement are 9.7373 and 5.6922, respectively, which are 2.7499 and 3.8296 higher than the original image.