The invention relates to a preparation method of a tin alloy/silicon/carbon electrode material. The method comprises the following steps: with a porous polymer as a carrier, depositing silicon oxide; mechanically mixing magnesium; carrying out high-temperature thermal reduction and acid treatment; filtering and drying the mixture; mechanically mixing a tin alloy; tabletting the mixture; and carrying out high-temperature sintering to obtain the tin alloy/silicon/carbon electrode material. The porous polymer is one of polyacetylene, polyacrylonitrile, polyaniline, polypyrrole and phenolic resin; the tin alloy is one of a nickel-tin alloy, a copper-tin alloy, an iron-tin alloy and a silver-tin alloy; the silicon source is one of tetraethoxysilane, silicon tetrachloride and trichlorosilane; an inner layer of the tin alloy/silicon/carbon electrode material is carbon and silicon in a porous structure; and an outer layer is the tin alloy with good conductivity and stable structure. The electrode material has the advantages of high specific capacity and long cycle lifetime, and has a good application prospect in the field of batteries.