The application of solar cell has offered human society renewable clean energy. As intelligent materials, crystalline silicon solar cells occupy absolutely dominant position in photovoltaic market, and this position will not change for a long time in the future. Thereby increasing the efficiency of crystalline silicon solar cells, reducing production costs and making crystalline silicon solar cells competitive with conventional energy sources become the subject of today's PV market. The working theory of solar cell was introduced. The developing progress and the future development of mono-crystalline silicon (c-Si), poly-crystalline silicon (p-Si) and amorphous silicon (a-Si) solar cell have also been introduced.