The effect of object-defocused state on the resolution property of confocal microscopy system(CMS) was analyzed and the defocused state was considered as the main factor of influence on the lateral resolution property of CMS.In order to diminish its efffect,shaping annular beam technique using binary otpics based on annular pupil filter technique was propopsed to improve the lateral resolution property of CMS under the defocused state.Experiments and analyses indicate that annular pupil filter technique used suppresses obviously the increasing of side lobe of Airy spot and the decreasing of CMS lateral resolution caused by the defocused state of CMS,and reaches the superresolution in the lateral direction.