Abstract: In order to achieve all-weather, multi-band, long-distance and real-time image monitoring, the optical front-end with low light level television, infrared and visible light system was designed, real-time multi-source image registration was investigated. Based on the parallel optical axis, the affine transformation parameters could be obtained by calculating the imaging disparity of the different field, the bilinear interpolation algorithm was used to make up the difference between infrared image and visible image in imaging, the infrared image transformation parameters were made into a look-up table stored in the image processor DM642, the system could quickly register different images through the look-up table and achieve real-time registration and synchronous fusion video. Experimental results indicate that this design can register multi-source images in real-time, the total processing time of image registration, image fusion and pseudo-color transformation is about 24.3 ms, the detection range is greater than 3 km.