Abstract: Taking the building in hot summer and cold winter zone as research object, the transient system simulation program（TRNSYS）simulation platform was used to build the active phase change energy storage floor module. The simulation model of the active phase change cold storage floor air conditioning system and the conventional fan coil plus fresh air conditioning system was established, and the energy saving and economy were simulated and calculated. The effects of chilled water temperature on energy storage and release characteristics of active phase change energy storage floor, room temperature fluctuation and coefficient of performance（COP） of heat pump were investigated under the condition of night cold storage operation in the cooling season and typical day. The results show that under the condition of phase change cold storage at night, the optimal chilled water temperature is 9 ℃ when the cooling load per square meter is 74.78 W. When the cold storage heat pump adopts the intermittent operation scheme with low electricity price at night, the COP of heat pump operation can be effectively improved with reduced operation cost. Compared with the conventional fan coil plus fresh air air-conditioning system, the energy consumption of the active phase change energy storage floor air-conditioning system in the cooling season is reduced by 30.5% with operating cost reduced by 44.24%, and the comprehensive refrigeration energy efficiency ratio reaches 2.38 in summer.