Abstract: For high-velocity spillways, a reasonable design of the air supply hole is one of the important factors ensuring its safe operation.However, at present, the cross-section size of the air supply hole is determined based on experience in the industry.Therefore, most projects have the phenomenon of excessive wind speed or insufficient air supply in the air supply hole.In this paper, the numerical simulation method was used to analyze the influence of the area of the air supply hole on the wind speed.The relationship between the wind speed in the air supply hole, the flow velocity and the area coefficient(the area of the air supply hole divided by the residual area of the air supply hole top) was established.The research results showed that by increasing the area of the air supply hole, the average wind speed in the hole decreased, and the fluency of the air in the hole could be improved.Based on the prototype observation data from Jinping Ⅰ Hydropower Station, it showed that the resulting error of the aforementioned wind speed prediction formula was less than 10%.At last, taking wind speed and air supply capacity as control indexes, a method to evaluate the rationality of air supply hole design was proposed, and the corresponding improvement measures were put forward.By adjusting the section size of the air supply hole, the wind speed can meet the requirements of the specification, and the air supply capacity can be guaranteed.