Abstract: Once a sudden event such as fire, collision, or water ingress occurs inside a large cruise ship, the impact of personnel evacuation gathering points, evacuation paths, and behavior on evacuation time is crucial. This article constructs a physical model of a cruise ship and uses FDS to simulate the entire process of fire and smoke spread, temperature field changes, heat release rate, CO concentration, and visibility in the cabin of the DECK 7-story internal fire scene. It also calculates the available safe evacuation time for the cruise ship's fire area to reach the critical evacuation environment and for personnel to safely evacuate to the assembly point; Selecting different storage locations for life jackets inside the cruise ship as important parameters affecting personnel evacuation time, using Pathfinder software to simulate the safe evacuation time of personnel directly to the assembly point and returning to the guest room to wear life jackets before evacuating to the assembly point. The results show that after about 386 seconds of the fire, the heat release rate reaches a peak of 3 990.21 kW and is accompanied by the occurrence of flashover. Corresponding ventilation devices and appropriate sprinkler devices should be installed in the cabin to start at the critical temperature, in order to reduce the probability of flashover and slow down the spread of the fire; When personnel are directly evacuated to the assembly point, the fire area of the cruise ship reaches the critical evacuation environment value and the available safe evacuation time for all personnel is greater than the necessary safe evacuation time; When personnel choose to return to the guest room and wear life jackets before evacuation, the fire area of the cruise ship reaches the critical evacuation environment value and the available safe evacuation time for all personnel is less than the necessary safe evacuation time. Therefore, compared to most cruise ships currently storing life jackets inside guest rooms, storing all life jackets at assembly points results in shorter evacuation times and can meet the safety requirements for fire evacuation. This further provides theoretical basis and technical support for optimizing the storage of life saving equipment inside cruise ships, constructing emergency scenarios, and guiding personnel evacuation.