A multi-sensor system consists of some pairs of space-fixed camera-projectors in which each of them can reconstruct a point cloud of an object at a corresponding view. The individual 3D maps obtained from them are then registered together to form the complete 3D shape of the object. However, the point clouds registration is still challenged by the global calibration of the multi-sensor system. To overcome this problem, this paper proposes a novel calibration method for a multi-sensor system with high accuracy. In which the spatial position information of the calibration units is used to construct the objective function while an optimization algorithm based on the mark reconstructionmethod is applied to the control point extraction process. Experimental results demonstrate that the proposed method is better than the conventional methods with an average center of gravity error of 5,729µm.