The invention relates to a video analysis-based space positioning method. The method comprises the following steps: 1, obtaining and storing coordinate information, parameter information and relevant attribute information of a plurality of cameras in a range; 2, obtaining and storing video data containing a target; 3, searching the video data containing the target according to the characteristic information of the target; 4, obtaining and storing the coordinate information of the target at every moment in real time according to the information of the position of the target relative to the cameras, and the position coordinate information, the parameter information and relevant attribute information of the cameras; and 5, obtaining the motion locus of the target according to the coordinate information of the target at every moment. The method fully utilizes the dense monitoring facility laid in the city scene, can rapidly position the accurate position of the target, can obtain the motion locus of the monitored target within a period of time, solves the accurate positioning problem in the complex city scene, and avoids the position description complexity existing in simple latitude and longitude positioning.