Abstract: In complex terrain, wind speed within the wind field can exhibit strong non-uniformity under the influence of strong typhoons. This paper takes the Maiwan Water Conservancy Project site in Tunchang County, Hainan Province, as an example, and uses Computational Fluid Dynamics (CFD) numerical simulation methods to analyze the site’s wind environment. The research results show that the incoming wind experiences varying degrees of reduction in speed when passing the dam site. The degree of reduction is related to the incoming wind direction. At wind direction angles of 45°-90°, the blocking effect of the adjacent mountains on the incoming wind gradually increases as the wind direction angle increases. At a 180° wind direction angle, the wind speed at the project site is higher due to the absence of mountain obstruction. Under a 0° wind direction angle and a wind speed of 60 m/s, the wind speed is higher at the intersection of the dam sides and the mountains. A gradient wind height of 300 m above ground level is considered reasonable for the project site, which is slightly less than the gradient wind height of 350 m specified for Category B terrain in Chinese standards.