In order to ensure the quality of whole optical system, it is important to measure and check the optical curvature radius accurately. The method of mechanical spherometer and the method of optical projection were combined, and the photoelectric image method was used to measure the vector height, then the radius could be calculated indirectly. The influence caused by edge error of measured element on the accuracy of the vector height and curvature radius was analyzed. Polarization imaging and general imaging were used to measure the height and compare the results, and it is found that polarization images can have better edge details, the accuracy of the vector height was effectively improved, and the error of the optical curvature radius was reduced by more than 0.5%. The results show that the method of polarization imaging has important application value in measuring the optical curvature radius.