As a self-developed UHV power transmission technology, large cross-section wire transmission and transformation is widely used, but after the completion of the crimping of the transmission line wire, the internal defects of the crimping tube are not easy to find, and the internal aluminum strand surface is scratched, stranded and other internal defects Seriously reduce the current carrying capacity and mechanical strength of the transmission line. In order to solve the existing problems, a simulation method for crimping and breaking of large cross-section conductor steel core aluminum stranded wire is proposed. Taking the JL/G1A-400/35 wire as an example, the damage of the aluminum stranded wire after crimping is modeled and calculated, and the strands are broken, the surface is damaged, and the aluminum stranded wire is not damaged. Stress condition at the time of breaking. The simulation results show that when the aluminum stranded wire is broken, the maximum stress of the broken aluminum strand reaches 802.6Mpa; when the aluminum strand is damaged, the maximum stress of the broken aluminum strand reaches 829.3Mpa; When the stranded wire is not damaged, the maximum breaking stress of the aluminum stranded wire is 865.2Mpa, which is the maximum value of the three cases. In the simulation calculation where the aluminum stranded wire is crimped first and then broken, when a pressure of 1010Mpa is loaded, the aluminum stranded wire can withstand the largest breaking force after crimping. The above simulation analysis results can provide a reference for the optimization of the crimping process of large cross-section conductor steel core aluminum stranded wire!