An energy-saving water tank aeration device mainly comprises a main floating vessel, and a floating vessel is arranged on each side of the main floating vessel, the main floating vessel and the secondary floating vessel are separated by a distance of not less than 60 cm, and the main floating vessel and the auxiliary floating vessel The top surface is provided with a body, and the main pontoon is provided with an electric module, the electric module mainly includes a deceleration unit, and the deceleration unit is connected to a motor unit and electrically connected and linked with the deceleration unit. The electric module further includes a waterproof cover for covering the reduction unit and the motor unit, the reduction unit is provided with a bearing, and a plurality of perforated accommodation bearings are disposed on the waterproof cover relative to the bearing. The two ends traverse and extend, and further comprise a plurality of connecting seats respectively connected to the bearing and the plurality of rotating shafts, and a plurality of blade sets are arranged on each of the rotating shafts.
