On the basis of analyzing the characteristics of low light level (LLL) image and ultra-violet image and the information amount of dual channel color night vision system, the LLL and ultra-violet color night vision technique is put forward. The methods of gray-scale modulation, frequency field fusion,special component fusion are tried, and the improved LLL and ultra-violet image pseudo color fusion algorithms are presented. These new algorithms include subsection gray-scale modulation, image difference picking-up, component separation based on the reflected characteristics to night skylight reflection characteristics of objects and color space mapping which embodies the spectrum response of image sensor and nature vision. Some good results are obtained.