The damage of transmission line caused by typhoon occurred frequently. In order to study the ultimate bearing capacity of transmission tower line system under typhoon load， the transmission tower-line system of a 220 kV transmission line in Guangdong Province is taken as the example in this article， that many towers was collapsed in a typhoon. The equivalent static wind load of the tower-line system is calculated by combining a recommended typhoon wind profile and the wind load calculation method of Chinese Load Code. The nonlinear of material and geometric characteristics of the tower is considered， and the ultimate bearing capacity of the transmission tower-line system is analyzed under step-loading by ANSYS. The influence on the ultimate bearing capacity caused by the wind directions， the deformation of adjacent towers， and the tension of the line is studied. The analysis results show that： 1） the ultimate bearing capacity of the transmission tower-line system and the most dangerous condition can be obtained by step-by-step upgrade analysis. 2） Finite element modal of tower-line system will influence the results the ultimate bearing capacity calculation. Taking more towers into the finite element modal will get more accurate result. 3） Choosing higher allowable initial force is benefit because the ultimate bearing capacity of the transmission tower-line system will increase with the initial tension of the line to some extent.