Trombe wall system is an effective passive solar heating, and phase change material can enhance its heat storage performance significantly. However, excessive heat loss during winter nighttime has been observed. Setting the curtain in air cavity can improve heat preservation of winter nighttime. The three-dimensional model of a phase change material-Trombe wall (TW-PCM) is established with FLUENT, and the influences of phase change temperature (PCT) and location of curtain/aluminum foil on thermal performance of the TW-PCM are obtained. It indicates that the total heat output reduces and the heating time extends for the TW-PCM, and the proportion of glass heat loss is over 50 %. The heat efficiency of the TW-PCM in the nighttime are significantly improved for TW-PCM with the curtain (CTW-PCM). For a TW with an air cavity width of 0.15 m, when the thickness of circulation air cavity exceeds 0.07 m (turbulent flow), heat efficiency is higher. The aluminum foil should attach to the external surface of the curtain.