The moving target detecting technology based on the in-door background was studied in this paper. Various kinds of object detecting algorithms were discussed

and the object detecting algorithm based on relatively immobile in-door background was put forward. The Gauss background modeling was used to distill perfect background frame which could be adaptive updated. Then the subtraction between the background frame and current frame was made to get the foreground of moving target in the video. Finally

the ideal target detecting result could be obtained after the noise was smoothed and eliminated.