The acoustic field of bottom bounce in deep sea is fluctuant and there are several discrete detected areas.To detect the target underwater，it’s important to establish quantitative relationship between the detected areas and the vertical beam pitch,and make sure that the vertical beam pitch is suitabe to aim at the detected areas.Through simulation of WKBZ,the paper points out that the formation of several discrete detected areas is related to periodic fluctuation of ray energy.When the sonar vertical beam pitch angle is the same with one angle whice corresponding ray energy peak value,high array gain can be achieved in one detected area.Based on the theory above,the paper gets the ray energy distribution numerical s with derivation,and puts forward a burst signal which includs several subpulses.Each subpulse can aim at one detected area through aim at ray energy peak,and the burst signal can aim at the whole bottom bounce area.The simulation results shows that the method achieves high array gain,and the envirimental adaptality is also excellent.Above all,the method has good application perspective.