The air conditioning system is an important component of the service system for the ship safety area. The function of the air conditioning water system is to transport chilled/hot medium water from the cold or heat source to the air treatment equipment. The air conditioning water system includes the chilled water system and the hot water system. The current study researches the impact of Safe Return to Port (SRtP) requirements on the design of the air conditioning water systems of large cruise ships, addressing the design ability for the SRtP of cruise ships. Firstly, the purpose of the design of the air conditioning systems for the SRtP of large cruise ships is presented based on the SRtP rules, and the basic design method of the air conditioning water systems for the SRtP of large cruise ships is also proposed. The configuration scheme, system principle and valve operation of the air conditioning water system for the SRtP of a large cruise ship are analyzed and studied to provide the design method of the air conditioning system of the activated safe area and the machinery space supporting SRtP. The results indicate that different design methods should be flexibly selected to simplify the design of SRtP. The research can provide references for the design of the air conditioning water system for large cruise ships in the future.