This thesis uses CFD software FLUENT to simulate the movement and heat transfer of the heat exchanger and get the temperature distribution. This thesis simulates the movement and heat transfer of the heat exchanger in steady work state, and compares the twisted-model’s heat transfer performance with the no-twisted-model’s. It points out that the design parameter of heat exchanger has deficiency, and suggests that the heat exchanger can be improved by reducing the velocity of air or by using short twisted tape instead of long twisted tape. The effect of the velocity of air to the twisted-tube’s or no-twisted-tube’s surface heat transfer coefficient is analyzed through the simulation to the single tube model. This thesis compares the difference between twisted-tube’s and no-twisted-tube’s heat transfer performance and points out that the velocity of air in the tube should be controlled below 20m/s.