To realize co- phase of segmented asphere aperture, a calculation system is build up for testing and alignment segmented mirrors. Curve fitting the surface data of the paraboloid mirror is made to establish coordinate matrix. The position deviation of sub-apertures is calculated by using transformation matrix. The simulation result shows that the segmented aperture achieves the initial accuracy. A two wave-length interferometer is used to detect the 600 mm paraboloid segmented aperture. Depends on the tilt error calculated form the surface data, the segmented aperture position deviation can be limited in the accuracy of a single aperture λ /15.