The invention relates to the technical field of ships, in particular to an externally-hung-type shape-preserving mine-preventing cabin. The externally-hung-type shape-preserving mine-preventing cabincomprises two parts of a main body and an auxiliary body, the main body comprises empty cabins which are arranged on a resistance-reducing liquid cabin and a function cabin chamber, resistance-reducing liquid is loaded in the resistance-reducing liquid cabin, and the resistance-reducing liquid cabin is connected with a discharging pump; the function cabin chamber is internally provided with a power source module and a control system, and the control system controls work of the discharging pump; and one face of the auxiliary body is fixed to the main body, and the other face of the auxiliary body is fixed to a ship body. According to the externally-hung-type shape-preserving mine-preventing cabin, through the deformation energy-absorbing principle, underwater exploding impact force acting on the ship body is effectively absorbed; through the shape-preserving design, change of the original gravity center, floating center and metacenter of a conveying ship is reduced, and the influence ofrefitting on the ship sailing performance is reduced; the ship overall streamline is optimized, and the resistance increment caused by the externally-hung cabin is decreased; and the resistance-reducing liquid for reducing viscous resistance is loaded in the mine-preventing cabin and discharged in the sailing process and wraps the surface of the ship body to reduce the resistance of the ship bodyand increase the sailing speed.