The invention discloses a high-capacity carbon-silicon negative electrode active material and preparation and application methods thereof. The high-capacity carbon-silicon negative electrode active material achieves a specific capacity of 800-1500 mAh/g and is formed by mixing carbon-silicon materials and graphite materials, wherein the carbon-silicon materials are microspherical particles prepared by performing ball milling spray-drying and thermal treatment processes on nanosilicon, crystalline flake graphite, carbon nanotubes and a carbon source, the nanosilicon is dispersed on the surfaceof the crystalline flake graphite, the carbon nanotubes are inserted into pores formed between the carbon nanotubes and the crystalline flake graphite, pyrolytic carbon of the carbon source is coatedon the surface of the nanosilicon and the surface and pores of the spherical particles formed by the nanosilicon, the crystalline flake graphite and the carbon nanotubes; the weight of silicon-carbonmaterials is 25%-80% of the total weight of the high-capacity carbon-silicon negative electrode active material. When uniformly mixed with conducting agent and bonding agent, the high-capacity carbon-silicon negative electrode active material can be coated or deposited onto copper foils, foamed nickel, foamed copper or carbon fiber paper as the negative electrode of a lithium ion battery. The preparation method of the high-capacity carbon-silicon negative electrode active material is simple in process, low in cost, applicable to amplified preparation of long-circulation carbon-silicon materials.