In this study, a numerical analysis method was used to simulate the solidification growth process of polysilicon ingots in a DSS450 prototype directional solidification crystal growth furnace produced by GT Advanced Technology. Finite element modeling was carried out using the finite volume method, which is contained in the commercial software package ANSYS Fluent. In the simulation, many actual parameters during production, including those of the heat transfer model, flow field model, and thermal radiation, should be employed in addition to the opening angle of the argon inlet channel. This opening angle was taken as the main parameter to simulate the effect of different angles (20, 60, 140°) on the temperature variation at different positions in a directional solidification crystal growth furnace. The settings of the simulation parameters referred to the actual growth process of the polysilicon directional solidification system. The temperature of each part in the crystal growth furnace was set at 1685 K, and the temperature in the molten silicon crucible was set at 1750 K. Finally, the growth state of the crystal silicon ingots was simulated in a transient manner, and the variation of the temperatures of melting polysilicon ingots at different positions (points) was discussed on the basis of the simulation results. The results show that for different opening angles of the argon inlet channel, different temperature fields are obtained in the furnace body during the solidification and growth processes of the crystal silicon ingots.