With global seawater temperature continuing to rise, there exists a potential risk of Component Cooling System (RRI) temperature at nuclear power plants in southern China exceeding design basis, which results in a reduction in the cooling capacity of Reactor Cavity and Spent Fuel Pit Cooling and Treatment System (PTR), affecting the removal of decay heat in the spent fuel pool. Taking a CPR1000 unit in China as an example, this paper completely analyzes the impact of increased seawater temperature on the cooling of spent fuel pool by establishing a quantitative evaluation model, and puts forward countermeasures. The results show that under the condition of RRI temperature exceeding design basis due to the rise of seawater temperature, there is still a considerable safety margin for the cooling capacity of the spent fuel pool in the case of complete unloading of one core under abnormal condition and design basis accidents. In the case of normal power operation and normal refueling outage, there is a certain challenge in the cooling capacity of the spent fuel pool, which can be addressed by adjusting PTR operation mode or decay time prior to commencing movement of irradiated fuel, so as to provide reference for the comprehensive decision-making of nuclear power plants.