Numerical simulation of sublimation SiC bulk single crystal growth was performed. Electromagnetic and temperature fields in a growth furnace were analyzed numerically. The relation between grown crystal shape and temperature distribution in a growth cavity was discussed. It is pointed out that the crystal shape has a close relationship with temperature distribution. By modifying the crucible design and temperature distribution in a growth cavity, it is possible to enhance the enlargement of grown crystal, and also possible to keep grown surface flat.