Abstract: Based on the carbon coating and addition of conductive materials, a small amount of nano-Si was doped to further improve the first charge and discharge capacity and the first coulombic efficiency. The phase structure and micromorphology of the materials were analyzed by XRD, SEM, TEM, Raman and FTIR, and the electrochemical properties of the composites were analyzed by a constant current charge-discharge test. The results show that the composites with 10% nano-Si (SiO_x-Si@C@carbon nanotubes(CNTs)-10) exhibit a first charge and discharge capacity of 1 348.1 mA•h/g and 1 874.4 mA•h/g, respectively, with the first coulombic efficiency of 71.9%. After 100 cycles, the reversible capacity of the composite is 1 116.2 mA•h/g, with the capacity retention rate of 82.8%. The discharge capacity is much higher than that of the material without nano-Si doping at different current densities. The SiO_x-Si@C@CNTs composites show high first coulombic efficiency, good cycle performance and rate performance.