Abstract: The incompressible fluid uniform flow model was used to simulate the passive containment cooling system (PCS) of HPR1000 in this paper. The thermal-hydraulic analysis of PCS was carried out under the condition of large break loss of coolant accident (LOCA) of reactor coolant system (RCS) and the performance analysis and calculation of PCS design conditions were carried out. The results show that the passive operation characteristics of PCS have a good matching ability with the accident process. PCS can start very quickly in the early stage of the accident and keep the temperature and pressure of the containment in a safe range within 24 h. According to the analysis of heat transfer performance of PCS design conditions, PCS enters the two-phase heat transfer stage after 5 h of operation, and can run steadily for a long time after the water in the tank reaches saturation temperature. The heat in the containment can be removed.