Czochralski (CZ) method based silicon crystal furnace is the main equipment to produce the solar cells silicon material. To meet the technological requirements of the silicon material for the solar photovoltaic industry, this paper introduces the role of mono-crystal silicon in the solar photovoltaic industry, and studies some key control issues in the silicon crystal growth process. Important achievements are obtained in the aspects of diameter measurement and control, heat field modeling and temperature control, design and implementation of the large-scale CUSP magnetic field as well as solid-liquid interface measurement and control etc. Experimental results show that the proposed solutions meet the technological requirements of silicon crystal growth process.