In order to improve lift and drag characteristics of ground effect aircraft, experiments are made by measuring lift, drag characteristics, and wake velocity fields with a downward-forward swept wing and a biomimetic wing. On the basis of analyzing the wing tip vortex flow field structure, the mechanism of wing lift and drag changes is discussed from the perspective of spanwise flow. The results show that within the ground effect zone, the downward-forward structure can effectively improve the flow characteristics of the wing, suppress the formation and development of wing tip vortex flow, increase the vortex center distance, the effect is made with the lift being increasing and drag force being decreasing, and the closer the wing is to the ground, the more obvious the effect is. On this basis, the concave convex leading edge can further optimize the flow characteristics of the wing, reduce the intensity of the wing tip vortex, and reduce the induced drag. In small clearance ratio and small angle of attack conditions, the biomimetic wing with a downward-forward sweep structure with a concave convex leading edge has the optimal navigation economy. This provides a reference for improving the flight performance of ground effect wings and promoting the development of ground effect wing design theory