The invention discloses a compressed nitrogen rotation-type foam proportionally-mixed fire extinguishing system, and relates to the technical field of fireproof and fire extinguishing systems. The compressed nitrogen rotation-type foam proportionally-mixed fire extinguishing system is mainly composed of a nitrogen cylinder set, a foam mixed liquor tank, a mixer, a control system, rotation-type compressed nitrogen foam sprayers and the like. According to the compressed nitrogen rotation-type foam proportionally-mixed fire extinguishing system, there is no need to start the fire extinguishing system with municipal electricity, and the fire extinguishing system is wide in applicability and particularly suitable for city tunnel fire extinguishment; the independent mixer is adopted in the system to mix nitrogen with foam liquid, mixing does not happen in any pipeline, mixing is made uniform, mixing time is short, a mixture is ejected out of all jet devices on a pipeline system after mixing is completed, no gas suction device is required on the jet devices, and thus the overall structure is simplified; and the mixed compressed nitrogen foam fire extinguishing capacity is high, the time is short, the burning temperature of a fire scene can be lowered to a great extent, and the casualty rate of fires is decreased.