Abstract: Reinforcing method, to constitute the box-shaped section by the angel of the transmission tower and the strengthening angle of the same size, was presented in the paper. In order to study the effect of every parameters on the bearing capacity of reinforced main member angle, analysis models of reinforced main member angles of single panel length and multi panel length were designed. Meanwhile, finite element analysis models of reinforced main member angles were also established by using ANSYS software. The reliability of finite element analysis was proved by comparing the results of finite element analysis and that from the experiments presented in references. The effects of the parameters such as the prestress force of high strength bolt P, the distance between ferrule assemblies L_t, the end clearance j_x, the length of subsidiary angle steel L_f, the thickness of ferrule plate t_g, the yield strength of angle f_y, the friction coefficient m_u, the wall leg thickness of angle used to strengthen the main member t_c and the section dimension of main members on the bearing capacity of models was researched. The results showed that the length of subsidiary angle steel L_f,the thickness of ferrule plate t_g,the friction coefficient m_u had little effect on the ultimate bearing capacity of the reinforced main members. The end clearance j_x and the prestress force of high strength bolt P had effects on the ultimate bearing capacity of NW series models with a small to medium slenderness ratio, and had little effect on the ultimate bearing capacity of other series models; the distance between ferrule assemblies had an effect on the ultimate bearing capacity of all reinforced main members.