The PEMFC driven unmanned aerial vehicle (UAV) is developing rapidly. However, the UAV has a compact structure and limited air source capacity. It is an urgent problem to improve the utilization rate of hydrogen that will further enhance the UAV endurance. In this paper, a hydrogen recirculation system based on the ejector is designed to recycle the drained hydrogen to improve the utilization rate of fuel. For the 1. 7 kW fuel cell used in UAV, a hydrogen cycle ejector is designed by using the computational fluid dynamics method, and the performance analysis is implemented to reveal the internal flow field characteristics under different working conditions. The results show that the primary flow pressure has a good ejecting performance in the range of 300 ~ 700 kPa when the pressure difference between the secondary flow pressure and the back pressure is 10 kPa. Then, the influence of key structural parameters of area ratio (AR) and different working conditions on the ejecting performance is studied. The research shows that the optimal AR varies with the change of primary flow pressure, and the AR is selected as 16 in this paper to meet the global optimal ejecting performance under different working conditions. The maximum hydrogen utilization rate of the proposed system is increased by 30. 3% outperforming that of the traditional UAV′s system.