The invention discloses a 
silicon carbon 
composite material, and a preparation method and an application thereof. The preparation method comprises the following steps of performing wet process ball milling on glass 
powder and a laminated layer carbon material to obtain a uniform mixed product of glass and the carbon material; next, performing uniform mixing and compacting on the product and 
magnesium powder and fused salt to form an 
ingot; and then performing a 
magnesium thermal reaction, and carrying out 
acid washing on the 
reaction product to obtain a sandwich layer-shaped 
porous silicon / 
graphene-like structured 
composite material. The preparation method are simple in steps and easy to implement, and the raw materials are wide in resource; more importantly, the mixture is made into the 
ingot through the compacting process, and then the 
magnesium thermal reaction is performed, so that the tap density of the 
silicon carbon negative 
electrode material is greatly improved, and the volumetric specific capacity of the negative 
electrode material is improved; meanwhile, by compounding with the 
graphite and other carbon material to form the sandwich-like structure, the 
electronic conductivity of the material is improved effectively, and the compatibility between the 
silicon base material and an 
electrolyte can be improved, thereby improving cycle performance and rate capability of the material; and therefore, the silicon carbon 
composite material can be applied to the negative 
electrode material with 
high power density and 
high energy density of the 
lithium ion battery.