The invention relates to a hydraulic safe relevelling device for an elevator. The hydraulic safe relevelling device comprises a position detection device, a levelling position magnetic grid, a movable rope hitch plate, a rope hitch assembly and machine room I-shaped steel, wherein the rope hitch assembly penetrates through the movable rope hitch plate and is fixedly connected with the movable rope hitch plate; and a relevelling adjustment device is arranged on the machine room I-shaped steel. According to the hydraulic safe relevelling device disclosed by the invention, the rope hitch assembly is fixed on the movable rope hitch plate, the movable rope hitch plate is installed on the machine room I-shaped steel through oil cylinders, the rope hitch assembly is driven to move with the movable rope hitch plate along a vertical direction through controlling the oil cylinders, so as to adjust the length of a traction steel wire rope to move a car, safe relevelling is realized through the relative movement of the car and the traction steel wire rope, sliding due to door-opening relevelling is effectively prevented, and the device is installed on the machine room I-shaped steel in a hoistway, does not occupy an overhaul space on a car roof, and facilitates maintenance for drive equipment; and in addition, the device is away from the car, and does not influence the lifting comfort of the car.