The microstructure and electrochemical property of nano-silicon alloy anode material are studied in this paper. The research shows that the outline of the nano-silicon particle is basically circular, and two copper-rich phases with different silicon contents are detected in the particle, and both phases with nanostructure are observed in its surface layer. The nano-silicon alloy negative electrode material needs to be used in a certain proportion with graphite, binder and conductive agent, and the stirring process also has an important influence on its electrochemical performance. The first-cycle coulombic efficiency of the material is improved to about 90%, and the specific capacity is still higher than 500 mAh/g after 100 cycles. The battery manufacturing process is similar to the graphite negative electrode, so it is easy to be applyed.