In security surveillance system, it is difficult for the spatial layout of cameras to achieve optimization. This paper presents a method for designing camera spatial layout in video security surveillance system under 3D GIS. Based on the Delphi method, five factors (namely, building layout, landscape, safety grade, entry and sustainable development) are extracted. Further, the basic principles and evaluation framework of the monitoring points' location are determined. Combining with multi-factor assessment, the camera imaging model and the a...