For the fixed infrared camera video surveillance, and the poor imaging results and limited monitoring range in the night and foggy weather conditions, we propose the zoom color video construction method in night and foggy days based on LED infrared camera with PTZ, combining with the characteristics of infrared imaging and visible light imaging. This method uses visible light imaging to achieve panoramic image stitching during daytime with good weather conditions, then the infrared image with the panoramic image is registered to construct a visible light background image with the same field angle. An infrared imaging system is used to extract moving objects in night and foggy days with low visibility, then through the mask fusion algorithm and the registration parameters, the moving target is fused to the same position of the visible light background image in the same proportion, and finally the zoom color video is constructed. The experimental results show that this method can meet the requirements of wide monitoring, real-time monitoring of color video in night and foggy all days.