To solve the problem of capturing artificial raised locusts in net house, a cyclone locusts capturing machine is designed. By using CFD software Fluent the airflow field in the suction nozzle and separate device is simulated. The test results of the sample machine indicated that when the inclination angle of suction nozzle was 75°, the airflow speed of the suction nozzle was 14m/s, the distance between the suction nozzle and ground was 40mm and the forward speed of the capturing machine was 0.4m/s, high rate capturing and low rate of break up were got. When practically working in locusts artificial raising net house, the airflow speed of the suction nozzle and the forward speed of the capturing machine were adjusted according to the distribution density of locusts on the ground, to improve the capturing efficiency and reduce the energy consumption.