To meet the urgent needs of high-precision measurement of centering error at home and abroad, a laser differential confocal centering error of the lenses measurement system is developed. The system starts from the core fixed focus principle of center-offset noncontact measurement, and combines the laser differential confocal fixed focus technology to solve the problem of poor resolution of the legal focus accuracy. On the basis of the error analysis of the optical measurement system, the system is optimized again and the position precisely corresponds to the cat′s eye and the confocal point of the lens under test, which realizes the high-precision measurement of the centering error of lenses. Compared with the traditional sharpness legal focus measurement, experiments show that the measurement accuracy of the system is 0. 49% , and the measurement accuracy of the centering error of lens is effectively improved by 6 times. The system effectively applies the differential confocal fixed focus technology to the centering error of lenses measurement, improves the fixation ability of the catenary and confocal position of the measured mirror, and realizes the design of a high precision measurement system, which has a broad application prospect in the field of optical testing and lens processing and assembly.