Fuel cell electric vehicles are an important development direction of new energy vehicles. As the core energy unit of the vehicle, fuel cell performance directly affects the economy, power and reliability of the vehicle. The ejector is an important functional element in the hydrogen circulation system of the fuel cell. Firstly, the ejector is designed and modeled based on the Sokolov design method. Then the flow field analysis of the ejector fluid is carried out. Finally, based on the analysis results, the key influencing factors of ejection performance are explored. The results show that under different pressure conditions, the ejection coefficient and the working fluid inlet diameter show a parabolic trend, and the ejection coefficient is positively correlated with the ejection fluid inlet diameter. The ejection coefficient first increases and then decreases with the increase of the mixed fluid outlet diameter. Based on the above-mentioned influence rules, the ejection coefficient is optimized, and the hydrogen return performance of the ejector is increased by 13.55%, which further improves the hydrogen utilization rate of the fuel cell, and further improves the ejector structure optimization and ejection characteristics research.