Two popular materials for multicrystalline Si ingot growth of the PV industry. Si3N4 and fused quartz, are working as composited material, tested and used to make industrial scale crucible. The main purpose of this composite material is to working as crucible for overcoming the low thermal conductivity of single fused quartz crucible during Si ingot process. Certain ceramic properties tests of the composite material, like porosity, density, are done with various percent of Si3N4/fused quartz, and thermal shock test did as well These results prove that our composite material is feasible to make square crucible for Si ingot process. Thus we simulate multicrystalline Si ingot growth and experiments are clone by industrial scale G5 crucible made by the composite material with optimal ratio of Si3N4/fused quartz. These results show that since composite crucible has higher thermal conductivity, the more heat flux could penetrate the bottom of crucible for Si directional solidification, correspondingly the temperature distribution, interface of solid-liquid Si, growth speed and grain structure, these kinds of key features of Si ingot process can be improved. The thermal profile analysis and photoluminescence picture show the improvement of Si ingot process using this composite crucible. Finally the considerations of industrial mass production using this kind of composite crucible are discussed. (C) 2014 Elsevier B.V. All rights reserved.