The metro axial flow fan was taken as the research object. A bionic wave leading edge design was proposed for the blade of axial flow fan inspired by the fact that the wave structure of the humpback whales flipper leading edge in nature can increase the hydrodynamic performance of the flipper. Through numerical simulation, the impact of the bionic wave leading edge's structural parameters (amplitude, wavelength, concave-convex structure and distribution length) on the fan's aerodynamic performance were examined. The results show that the convex bionic wave leading edge is generally better than the concave and convex bionic wave leading edge at whole flow range. The convex bionic wave leading edge enhanced the fan's total pressure by 11 Pa and total pressure efficiency by approximately 3% under the design flow rate, while the concave and convex bionic wave leading edge decreases the fan's total pressure and efficiency. The best amplitude, wavelength and distribution length are 4, 8, 144 mm for the biomimetic wave leading edge, respectively. By integrating the optimal geometric parameters, the modified fan exhibits a 3.12% increase in total pressure at the design flow rate, reaching 562 Pa. While the total pressure efficiency is enhanced by 3.30%, achieving a value of 81.55%.