Compared with preparation of solar grade multicrystalline silicon(SOG-Si) by improved Siemens method,new silane method and fluidized bed method,metallurgical processing of SOG-Si is considered as an important way to solve the shortage of silicon feedstock supply and to reduce costs for Photovoltaic industry,which has promoted signification to the widespread use of solar energy.The fundamental principles of removal of metallic and non-metallic impurities in metallurgical grade silicon(MG-Si) during metallurgical processing of SOG-Si is discussed,and research progress on metallurgical processing technologies of SOG-Si is introduced