Due to the rapid development of China’s rail transportation equipment manufacturing industry and related international distribution,important material suppliers such as Baoshan Iron & Steel Co.,Ltd.carries on investigating the stability of material under extremely cold conditions.In this study,mechanical properties and secondary work embrittlement of weathering steel 05 CuPCrNi were tested at low temperature.Compared to the mechanical properties at room temperature,the yield and tensile strength increase slightly with decreasing temperature.However,the variation of elongation is not obvious.The experimental results also show that the secondary work embrittlement transition temperature of 05 CuPCrNi is lower than-60 ℃.These results provide the basis for the use of this train body material in extremely cold regions. Due to the rapid development of China’s rail transportation equipment manufacturing industry and related international distribution, important material suppliers such as Baoshan Iron & Steel Co., Ltd.carries on investigating the stability of material under extremely cold conditions. In this study, mechanical properties and secondary work embrittlement of weathering steel 05 CuPCrNi were tested at low temperature .Compared to the mechanical properties at room temperature, the yield and tensile strength increase slightly with decreasing temperature .However, the variation of elongation is not obvious. The experimental results also show that the secondary work embrittlement transition temperature of 05 CuPCrNi is lower than -60 ° C. These results provide the basis for the use of this train body material in extremely cold regions.