The present invention relates to a porous silicon-silicon oxide-carbon composite comprising a silicon oxide-carbon structure and silicon particles, wherein the silicon oxide-carbon structure comprises a plurality of micropores, and the silicon particles are uniformly distributed in the silicon oxide-carbon structure. The porous silicon-silicon oxide-carbon composite of the present invention has a reduction in the volume expansion due to the insertion of lithium ions, has improved electrical conductivity, and has a porous structure, and thus an electrolyte can easily permeate into the porous structure to improve output characteristics, so the inclusion of the porous silicon-silicon oxide-carbon composite in a negative electrode active material can further improve the performance of a lithium secondary battery.