Abstract: In view of problem that background of field video of video monitoring in dangerous area of mine is complex, so as to be difficult to realize accurate extraction of video object, the paper proposed a video detection algorithm for object based on background registration. Implementing steps of the algorithm are as follows: extracting SIFT feature points and calculating H-S optical flow vector of the feature points area; extracting motion area of background by analyzing area motion performance and making frames matching for feature points of motion area of background; calculating affine parameters and extracting accurate object area after registration and difference. The experiment result showed that the algorithm can remove influence of feature points of foreground object on background registration and can gain accurate object area.