The invention relates to a
porous silicon material and a preparation method thereof. The method for preparing the
porous silicon material comprises the following steps: carrying out an in-situ catalytic reaction between a
silicon material and
chloromethane at the temperature of 401 to 800 DEG C in the presence of a
solid copper-based catalyst, and preparing the
porous silicon material through calcining, acid
pickling, alkaline washing and other after-treatment
impurity removal technologies, wherein the
solid copper-based catalyst comprises one or a mixture of more than two in primary catalysts such as CuOx, CuCl and CuCl2, x is more than or equal to 0 and less than or equal to 1, as well as a small amount of secondary catalysts. Reaction condition parameters are regulated, so that the pore size, pore size distribution and
porosity of the
silicon material can be regulated. According to the method, a porous
silicon material which is difficultly obtained in the patented technology at present is obtained, and important organic silicon
monomer chemicals can be obtained. The porous silicon material prepared by the method is uniform in pore size, low in production cost, simple in process and suitable for industrial production and has wide application prospects.