Cylindrical vector beams are spatially inhomogeneously polarized, whose intensity in the center is zero, and can produce special field components in the vicinity of focus when they are focused by an objective lens. In the case of optical system with high apodization factor, radial polarization can achieve tight focus by adapting pupil filtering and image restoration technology compared with linear and circular polarization. The properties of cylindrical vector beams are introduced. Based on electric dipole radiation model and vector diffraction theory, focal field properties for cylindrical vector beams focused by a high-NA objective lens are discussed. The method to achieve tight focus by cylindrical vector beams is presented. Furthermore, we consider it feasible for the super resolution laser polarized differential confocal microscopy by adapting the differential confocal microscopy, and put forward the prospective development.