Abstract: In order to improvelaser beam quality of unstable cavity high energy laser systems and the utilization of the aperture of a transmitting optical system, a new optical shaping method for the annular beam was proposed. Optical elements were added to the light path outside the laser cavity to shape the output of annular laser beam. On the basis of theoretical analysis, beam shaping devices based on dual axicons were designed and fabricated. The shaping experiments were carried out for the annular beam from an unstable cavity high energy laser. The data was obtained and was consistent with theoretical analysis.The results show that, the beam after shaping by using dual axicons has better beam quality than that of the original beam. Waist diameter decreases from 45mm to 32mm. M² factor reduces from 14 to 11.8. The method is feasible for the shaping and transformation of the annular beam from an unstable resonator.