Abstract: With the aim to measure the radius of curvature deviation of spherical lens online in workshop, based on the laser testing technique, a solution of miniaturization sphericity interferometer system without precision guide was proposed, and the principle of the system was analyzed. After the analysis by Zemax simulation, the system could get the astigmatic and local deviation of lens, and measure the radius of curvature deviation fast. The results show that the precision of radius of curvature deviation is better than 0.01%. Compared with the existing sphericity interferometers, the new system is particularly fit for noncontact online testing in workshop, and has advantages of compact structure, no precision guide, high efficiency and low costs.