Software simulation and sample measurement were conducted to investigate the factors affecting the thermal performance of dye-doped liquid crystal (DLC) smart window, including the position of DLC dimming glass and the type of Low-e layer. The results indicated that when the DLC dimming glass was placed on the outdoor side and triple silver Low-e layer was arranged at position 2# of insulating glass, the optimal thermal performance was obtained, with the Shading Coefficient (SC) of 0.14 ~ 0.27 and the Heat Transfer Coefficient (K) of 1.33 W/(m2?K).