The invention provides a preparation method of a silicon-based lithium ion battery negative electrode material. The method mainly comprises the steps of designing a nitrogen-doped graphene-coated silicon sphere three-dimensional network of which defect induced stress is arranged again; preparing spherical nanometer silicon by a thermal plasma method; preparing a nanometer silicon template by a mechanical method; and preparing the nitrogen-doped graphene-coated silicon-based lithium ion battery negative electrode material by the nanometer silicon template and by a chemical vapor deposition method. A stress concentration principle in elastic mechanics is applied to design of the material, kilometer-scale nanometer silicon powder is prepared by the thermal plasma technology, nitrogen-doped graphene-coated silicon is prepared by the chemical vapor deposition method, and industrial production on a large scale is achieved; the stress concentration principle is introduced, the nitrogen-dopedgraphene-coated silicon is designed and optimized and has more stable structure, and more stable circulation is achieved; and the nanometer silicon prepared by the method has the advantages of smallergrain size, relatively good dispersing performance, relatively high yield and the like.