The polarization change of the hollow beam (HLB) is theoretically studied， and its focusing characteristics are studied based on the Richards-Wolf vector diffraction integral theory. The changes in the size and shape of the focused spot at different numerical apertures are obtained. It is found that the circularly polarized hollow beam and the vertically polarized hollow beam mainly changes in the size of the focused spot， while the horizontally polarized hollow beam and the radially polarized light book change greatly. In addition， a method of converting the vector polarized hollow beam into the scalar polarized hollow beam is proposed. The polarization state of the hollow beam is converted and the power compensation is obtained. The average power of 2.2 W laser output is obtained.