Li2FeSiO4-xSx/C (x=0,0.01,0.02,0.03) nano cathode materials were prepared by solid state reaction. The micro morphology, crystal structure and electrochemical properties of the materials were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (Raman), infrared absorption spectroscopy (FTIR) and constant current charge discharge tests. The results show that the Li2FeSiO3.98S0.02/C morphology is nano spherical, and the average particle size is 45.38nm. The nano particle size is conducive to shortening the diffusion path of Li+; Carbon coating can inhibit the growth of nanocrystals and enhance the conductivity of materials; Sulfur doping can expand the tunnel spacing of materials and improve the magnification performance of materials. Li2FeSiO3.98S0.02/C shows high charge discharge specific capacity, excellent rate performance and cycle stability. The specific capacity of the first discharge at 0.1C is up to 180.1mAhg-1, and the capacity retention rate after 100 cycles at 10C is 91.3%.