Disclosed are an automatic stable posture seabed base and a releasing method, belonging to the technical field of ocean observation. The automatic stable posture seabed base includes an accommodating body with an inner cavity for accommodating the first observation device and a seawater, and the accommodating body has first through holes for the seawater to enter and outflow the inner cavity; plugging members blocked at the first through holes to close or semi-close the first through holes; and a buoyancy body installed at a transducer of the first observation device, and a buoyancy of the buoyancy body is larger than a mass of the first observation device, so that the first observation device may float in the cover body after the cover body is filled with water, and a posture of the transducer in the cover body always keeps vertically to the sea surface.