Circular targets are widely used in visual measurement fields such as augmented reality, photogrammetry, and structured light projection measurement systems. However, the eccentricity error of circular targets caused by perspective projection seriously affects the measurement accuracy. In order to improve the accuracy of projection center positioning, an accurate projection center positioning method with concentric circles as the target was proposed. This study mainly includes an improved projection center positioning method and iterative compensation considering lens distortion. The use of ratio invariance avoids the eccentricity error caused by perspective projection of circular targets, and then the improved projection center coordinates are added to the iterative calibration process to eliminate the influence of lens distortion on center positioning, so as to accurately locate the projection center. Experimental results show that the proposed method can accurately locate the projection center and has good performance in camera calibration.