Porous silicon has the characteristics of large specific surface area and good luminescent properties. At present, the research on porous silicon has been involved in the fields of biological and chemical sensors, drug delivery, photocatalysis, energy and so on. The pore of porous silicon can effectively reduce the volume expansion in the process of silicon lithiation, shorten the distance of lithium ion diffusion from electrolyte to silicon, and promote the charge-discharge process at high current density. Therefore, porous silicon has been widely studied and developed in the field of energy storage. However, some challenges still exist, such as preparation cost, etching mechanism, regulation of porous structure, and electrochemical performance of porous silicon, which cannot meet the requirements of commercial application. The current research on the preparation methods of porous silicon at home and abroad is reviewed in this paper, and the application of porous silicon in lithium ion battery is introduced in detail. Finally, the development of porous silicon materials in energy storage field is prospected.