The output properties of high-power hollow CO2 (or CO) laser are analyzed in this paper.The propagation characteristics and light intensity distribution of the hollow laser beam are studied in detail.The analytical expression of the beam in the near field is given out.The results indicate that the output beam has a dark area in the center.The hollow laser beam can be applied to the plate photography,material processing,optical tweezers,optical spanner,laser drilling and so on.