The transmission tower-line system exhibits characteristics of high elevation and long spans, leading to fragility under strong wind. This study aims to investigate a case of tower collapse hit by typhoon Doksuri, in 2023. Considering the buckling and damage of angle steels, a nonlinear constitutive model was employed to simulate tower collapse. Collapse wind speed was determined as 35.8 m/s, based on the simulated result and the measured wind speed. The damage of elements and segments was investigated to identify the weak position of the tower. The results indicated that the buckling of diagonal elements caused the collapse. Segments with sudden changes in stiffness were identified as weak positions. Through sensitivity analysis, the influence of uncertainty parameters was studied. Displacement is significantly influenced by uncertainties in elastic modulus and yield strength. The proposed multi-line constitutive model effectively simulates the collapse progression and critical wind speed of transmission towers, offering valuable design references.