The invention discloses a porous silicon/graphite compound lithium battery negative material, and belongs to the field of preparation of negative materials. Aiming at the defects that the interface contact between a silicon material and a carbon material is relatively poor, and the inner wall of a pore of the silicon material can not be wrapped completely, the invention provides a method which comprises the following steps: putting a polycrystalline silicon wafer into acetone and absolute ethyl alcohol, cleaning, grinding into particles, loading carbon particles onto polycrystalline silicon peach gum particles through high-speed air flow under wrapping and adhering actions of peach gum concentrated liquor, and finally performing calcining and grinding, thus preparing the porous silicon/graphite compound lithium battery cathode material, wherein porous silicon can be effectively wrapped by carbon. Due to combination of the silicon and the carbon, the polarization reaction of the silicon material is reduced, corrosion caused by the contact between metal serving as a negative material and battery electrolyte is reduced, the capacity is increased by 20 to 35 percent, the carbon is perfectly loaded on the polycrystalline silicon, the service life of a battery is greatly prolonged, and the service time is prolonged by 20 to 30 percent.