:A new method of point target detection is presented in order to solve the problem of point target detection in the infrared surveillance system. The method consists of three steps. First , the background in the image of single band is predicted and restrained ; Second , the images of two infrared bands are fused after they are done the adaptive threshold value ; Finally , the result of target detection is given by the analysis of the image sequence. The experimental results show that the performance of background restraining is very good and the number of the candidate targets decreases greatly , so the method can improve the performance of the point target detection.