In order to investigate the influences of different forms of reinforced section and initial load on mechanical behaviors of axial compression angle steel in steel tower following weld reinforcing process, two forms of reinforced section, square and Lshape, were selected. Under the four different initial load, the static load test of angle steel reinforced by welding was conducted. The loaddisplacement curve, the ultimate stability bearing capacity as well as the failure mode of reinforced angle steel were obtained. According to the static test, finite element models were established and the numerical simulation was carried out to take into account the indirect thermostructure coupling analysis method. Both the test and analysis results show that the failure mode of two reinforced sections are global bending buckling; Compared to the specimens with square cross section, Lshape specimens are more sensitive to the heat input, but ductility is poorer; If the nominal stress ratio of initial load is less than 0.3, the effect of initial axial compressive load on the ultimate stability bearing capacity of angle steel axial compression members reinforced by welding is negligible.