Spent fuel storage and passive cooling system

The embodiment of the invention discloses a spent fuel storage and passive cooling system. The spent fuel storage and passive cooling system comprises a container subsystem, a cooling subsystem, an exhaust subsystem and a water replenishing subsystem; the exhaust subsystem is connected with the cooling subsystem and is used for ensuring that the container subsystem is always in a full water state and ensuring natural circulation of the cooling subsystem; the water replenishing subsystem is connected with the container subsystem and the cooling subsystem, and the water replenishing subsystem is used for controlling the container subsystem to replenish water in time; all the container subsystems, all the cooling subsystems, the lower portion of the exhaust subsystem and the lower portion of the water supplementing subsystem are located below the sea level, and the container subsystems and the cooling subsystems are filled with boron-containing water or demineralized water. The problems that when an existing coo