Constant-temperature water trough

The invention discloses a constant-temperature water trough, and belongs to the technical field of livestock breeding, and the technical scheme is that the constant-temperature water trough comprises a water tank and a heater arranged in the water tank, the water tank is provided with a water drinking opening allowing the mouth of an animal to extend into, an annular piece is fixedly arranged in the water drinking opening, and the lower portion of the annular piece is a lower conical ring with the lower end expanding outwards; a floating body blocking the lower conical ring under the action of buoyancy is arranged in the water tank, and the highest point of the floating body is located in the annular piece all the time. The device has the advantages that the floating body arranged in the water tank can block the water drinking opening in the water tank through buoyancy, animals can normally drink water by pressing the floating body, and water pollution caused by open air is reduced; the controller receives a