The horizontal axis wind turbine is prone to flow separation during operation, which can affect the flow characteristics of the wind turbine and lead to performance degradation. As one of the methods of passive control, the leading-edge protuberances of the humpback whale have been proven to suppress flow separation and enhance performance. This study employs biomimetic principles to investigate the flow control mechanism by adding bionic leading-edge protuberances to wind turbine blades. The three parameters (amplitude, attenuation and number) that control the protuberances are nonlinear and non-uniform. The influence of leading-edge protuberances on the aerodynamic performance of a wind turbine is analyzed via the computational fluid dynamics method. The results indicate that the addition of protuberances can improve airfoil performance, increase the low-pressure area, and delay flow separation. For the single leading-edge protuberance, the pressure coefficient of the peak section decreases, and the pressure coefficient of the trough section on both sides increases. In this research, the bionic protuberance parametric structure applied to the blade leading-edge of the horizontal axis wind turbine proposed is a supplement to the existing bionic design method, which provides new research data for improving the design of wind turbine blades by using biomimetic principles. In addition, it holds practical value for guiding practical applications.