Toward the problems of theoretical error and the distribution status of the observed which can influence on camera calibration accuracy, a grouped approach algorithm based on exact measuring angle method is proposed. The proposed algorithm is composed of two parts: the method of adjusting the zero point of precise rotating platform is put forward to reduce the theoretical error, and the method of weighted theory is used to approach group data processing to eliminate the influence on the calibration result. Finally, the accuracy of grouped approach algorithm is analyzed. Experimental results show that principal point accuracy and the principal distance accuracy obtained by the proposed algorithm are reduced to 2.12 μm and 4.02 μm and improved by 2.43 times and 2.00 times respectively, comparing with the traditional exact measuring angle method in the same laboratory environment. The experimental results indicate that the calibration accuracy has been improved greatly.