With the characteristics of un-touching, high-automatic and high-speed, we measured 3D shape by digital moiré patterns. And it can measure 3D shape without compensator, auxiliary mirror, hologram and other assistant modules. So it is widely used in measurement of 3D shape. But with the negative effect of grating area and CCD resolution of the camera, it has some problems in large aperture, steep aspheric surface, even off-axis aspheric testing. Focus on these problems; this paper established a sub-region splicing measurement of aspheric surface by using the combination of digital moire patterns and digital phase shifting technology. This paper also illustrated the basic theory, and the mathematical implementation procedure. In all, sub-region splicing digital moiré patterns can be considered as another method, which beyond compensation tests to measurement of aspheric surface.