The invention relates to a water pushing oxygenation device of a culture pond. An output shaft of a submersible motor is coaxially connected with an air flotation shaft, the front end of the air flotation shaft is connected with an air flotation device in an air flotation cover, the outer wall of the air flotation cover is communicated with an air pipe, and the air pipe upwards penetrates a diversion barrel and extends to space above water; the submersible motor is connected with an input end of a speed reduction box, an output end of the speed reduction box is assembled with a propeller shaftthrough a three-stage gear in a meshed manner, the propeller shaft and the air flotation shaft are coaxially arranged outside the air flotation shaft in a sleeved manner, and a propeller is fixed onthe propeller shaft and positioned in rear of the air flotation cover; only the front end of the diversion barrel is open, and the diversion barrel wraps the air flotation cover and the propeller in space surrounded by the diversion barrel. An aeration device is not needed, so that blockage of an aeration hole is avoided, and maintenance work and cost are reduced; the water pushing oxygenation device is uniform in water pushing flow speed and good in adjusting performance; the air flotation cover utilizes negative pressure to suck air in, so that airflow stability is high, and adjustability ishigh.