A water cooled draft beer machine comprises a cabinet, and there is a refrigeration circuit inside the cabinet, including a compressor, a condenser and refrigeration tubes. A water tank is arranged inside the cabinet, and the refrigeration tubes are coiled inside the water tank. Inside the cabinet, there is a cold storage chamber. A beer pipe is arranged inside the cabinet, and a beer tap is connected to the outside of the cabinet. The beer pipe coils inside the water tank, and is connected to the beer tap. A refrigeration box is arranged in the cold storage chamber, and the cold water tube coils inside the refrigeration box. The inlet end and the outlet end of the cold water tube are both connected to the water tank. An air inlet and an air outlet are set up on the refrigeration box. A fan is arranged inside the refrigeration box.