Abstract: The feature point extraction of calibration target during the camera calibration is crucial and may affect the precision of camera internal and external parameters. Based on several typical camera calibration targets, a spot array target is designed as required by the fringe projection 3D profile measurement system. According to the image edge processing theory, a new method for feature point extraction of the spot array target is introduced, which includes the analytical characteristic theory of circle, the coordinate transformation, the corresponding relation of spot and circle, and statistical theory. The validity of this method is verified by experiment. This work can be used to solve camera internal and external parameters.