采用分子静力学方法模拟了〈100〉单晶铜纳米线的拉伸变形过程,研究了纳米线屈服的机理.结果表明:1)纳米线初始屈服通过部分位错随机激活的{111}〈112〉孪生实现,后继屈服通过{111}〈112〉部分位错滑移实现;2)纳米线变形初期不同滑移面上的部分位错在两面交线处相遇形成压杆位错,变形后期部分位错在刚性边界处塞积,两者都阻碍位错滑移,引起一定的强化作用. The tensile deformation process of <100> single crystal copper nanowires was simulated by molecular static method, and the mechanism of yielding of nanowires was studied. The results show that: 1) the initial yielding of nanowires is controlled by {111} <112 > Twins, the succession of yielding is achieved by the partial dislocation slip of {111} <112>; 2) part of the dislocations on the different slip planes of the initial deformation of nanowires meet at the intersection of the two sides to form the bar dislocation, Dislocations are plugged at rigid boundaries, both of which impede dislocation slip and cause some strengthening.