Abstract: Using multi-level observation data of the near-surface layer on the Weizhou Island, Beihai, Guangxi, this study examined the periods influenced by Typhoons Yagi, Sanba, and Talim during 2023–2024. First, quality control and correction were conducted on the observation data for each event. Subsequently, the structural characteristics of the typhoon boundary layer under the influence of the complex underlying surface of the Beibu Gulf islands were analyzed. The analysis included near-surface wind field evolution, wind profile characteristics, and variations in aerodynamic parameters, namely, friction velocity (u_*), roughness length (z₀), and drag coefficient (C_d), along with near-surface wind speed and direction. The results indicate that the typhoon boundary layer within 10–32 m exhibits near-neutral stability and the mean wind speed profile follows a logarithmic distribution. Under the influence of the complex underlying surface of the Beibu Gulf islands, the variations in u_*, z₀, and C_d with near-surface wind speed exhibit characteristics typical of a land underlying surface, showing obvious nonmonotonicity, and cannot be simply categorized as those typical of a homogeneous marine underlying surface. Specifically, u_* ranges between 0.5 and 1.5 m s⁻¹; when the 10 m wind speed exceeds approximately 15 m s⁻¹, the magnitudes of z₀ and C_d are on the order of 10⁻² m and 10⁻³, respectively. The u_*, z₀, and C_d values are generally higher under easterly winds than under westerly winds. The findings contribute to a deeper understanding of typhoon boundary layer structures over the complex underlying surface of an island and hold significance for optimizing numerical simulations and parameterization schemes of typhoons in the Beibu Gulf.