The invention discloses a novel anti-capsizing device for ships, -relates to the technical field of ships, includes the hull and bottom unit; A bottom device is arranged at the bottom of the hull, thebottom device comprises a rectangular steel frame, central keel, - telescopic device, A central keel is arranged at the central position inside the rectangular steel frame, two expansion and contraction devices are arranged inside the rectangular steel frame, the telescopic device comprises a retracting and releasing mechanism, telescopic mechanism, balanced floating plate, gear transmission mechanism, driving mechanism, high power intelligent motor and frame, A telescopic device is telescopically spread and attached to that water surface by a balanced floating plate, to maintain a stable condition of the ship at low speeds or moorings, The invention improves the safety and stability of the ship when sailing at sea, locks the telescopic device at high speed through the driving mechanism,avoids the influence of external environment on the telescopic device, and opens the telescopic device at low speed or mooring state, so as to facilitate the adjustment of the telescopic device to keep the ship stable.