This study constructs a cable prefabricated compartment model through FDS numerical simulation, simulating the temperature distribution and smoke diffusion patterns inside the compartment during cable fires, and explores the inhibitory effect of a perfluorohexanone fire suppression system on cable fires. The study shows that when a fire occurs at the bottom of the cable compartment, the temperature continues to rise vertically, followed by an increase in temperature at both ends of the compartment. The smoke rises to the top to form a roof jet, and as the thickness of the smoke at the top becomes larger, the smoke spreads to the entire cable compartment. Installing a perfluorohexanone fire extinguishing system can quickly and effectively reduce the heat release rate and temperature of the cable compartment, thus suppressing the spread of fire. The research findings can serve as a reference for public emergency fire response technology in cable compartments.