In this perspective, we reviewed the fabrication technologies of various silicon micro-nano structures and their applications in novel type of solar cells. The recent progress in the application of silicon micro-nano structures in traditional p-n junction solar cells, radial p-n junction solar cells and hetero-junction solar cells are discussed respectively. We then shown the recent efforts to improve the energy conversion efficiency of the solar cells with silicon micro-nano structures, including enhanced absorption of incident light, as well as surface modification and surface passivation of silicon micro-nano structures. Finally, brief overview and outlook are provided on the development of flexible silicon solar cells.