Abstract: In order to meet the demand of precision measurement of radius of curvature, precision ROC measurement system was designed based on laser interferometry. High precision, non-contact ROC measurement of optic elements was achieved, whose diameter was 100-300 mm and ROC 500-200 mm. The factors of ROC measurement results was analyzed and combination of standard uncertainty was caculated. Installation and adjustment of the system and verification experiments was finished. The relative uncertainty of ROC experiment results is above 710-6, it can meet the design demand of 1010-10.