This article investigates the influence of different Gurney flap parameters on rotor aerodynamic performance by establishing a three-dimensional blade model , a three-dimensional numerical method for rotor aerodynamic characteristics with Gurney flap was first established. The simulation method was then validated using typical experimental data. The effects of different lengths, heights, and radial positions of the Gurney flap on the aerodynamic performance of the rotor were then analyzed. Finally, by analyzing the pressure distribution on the blade surface, the pressure coefficient at the Gurney flap location, and changes in streamlines after installing the Gurney flap on the blade, the lift augmentation mechanism of the rotor blade equipped with the Gurney flap was preliminarily explored. The results show that when the Gurney flap height is 2%c, the length is 0.2R, and the center position is 0.7R, the rotor thrust increases by up to 14.15%. The double vortex structure formed behind the Gurney flap creates a suction effect on the upper surface of the airfoil, which can delay flow separation on the upper surface of the blade, thereby enhancing the rotor thrust.