The invention discloses a preparation method of a lithium ion battery silicon oxide composite negative electrode material, the method includes the following steps: (1) weighting a certain amount of silicon oxide SiOx, organic carbon and a graphite oxide precursor raw material for ball milling for 0.5-24 h to fully mix the precursor raw material; and (2) calcining the mixed precursor raw material in a protective atmosphere at 600-1400 DEG C for 0.5-12 h, and performing post-processing to obtain the silicon oxide composite negative electrode material. Through silicon oxide disproportionation, silica nanoparticles are distributed evenly in silicon dioxide, by organic carbon splitting decomposition, carbon coating is obtained, the probability of the formation of a SEI (solid electrolyte interphase) film in the material charge and discharge process can be reduced, the material electrochemical cycle stability can be improved, and by addition of graphite, good conductivity and ratio stability performance can be provided for the material. The production process is simple, raw material is cheap and easy to obtain, equipment is general, and mass production is easy.