Abstract: Under orthographic projection, a 3D reconstruction method based on rank 1 matrix containing all the image points in all views is presented in the paper. In the method, the unknowns are the 3D motion and relative depths of the set of points, not their 3D positions. The coordinates of the points along the camera plane are given by the first image positions. The knowledge of the coordinates along the camera plane enables us to solve the projective reconstruction problem by the factorizing the rank 1 matrix. Experiments with both simulated and real data show that the method has high precistion in 3D reconstruction.