For high-speed and high-accuracy of aberration inspection process for pickup lens of optical head for digital versatile disc (DVD), an optical system based on shearing interference of spherical wavefront from pickup lens using grating has been applied. A simple algorithm, that processes points allocated on certain lines in fringe and fits relations between distance from basis point to the measurement points and phase difference at these points to equations of higher degree as curve fitting, has been devised. Coma, astigmatism and SA3 have been numerically estimated as the size of certain coefficient Inspection system based on this optical system and algorithm has been developed. Difference of measured value between the developed system and the conventional interferometer that has been treated as the standard is 3.9mλ and below at σ, this value is equal to difference between two conventional interferometers. Therefore accuracy of the developed system is equal to conventional interferometer. In comparison with the conventional spot system, this system has obtained higher accuracy, as well as 1/3 inspection time and 1/2 and under tact time.