The invention discloses a constant-temperature, automatic and independent drinking water system. The constant-temperature, automatic and independent drinking water system is characterized by comprising a water tank buried underground, a water inlet pipe, a water outlet pipe and a water return pipe, wherein the water inlet pipe, the water outlet pipe and the water return pipe are communicated with the water tank, a water inlet main valve and an overflow valve are arranged on the water inlet pipe, a water pump is connected onto the water outlet pipe, an automatic water supply adjustment device is connected onto the water pump, a plurality of drinking water troughs are communicated with the automatic water supply adjustment device, a water return valve is arranged on the water return pipe, and the drinking water trough at the tail end is communicated with the water return pipe. The automatic water supply adjustment device comprises a water box, a floating ball valve installed in the water box and an electric control switch installed between the floating ball valve and the water pump. The constant-temperature, automatic and independent drinking water system has the advantages that the water tank is buried underground, and water in the water tank is heated by utilizing terrestrial heat and kept to be at the constant temperature; automatic water supply of the drinking water system is achieved through the water pump under the control of the floating ball valve and the electric control switch, artificial monitoring of water volume in the water tank is not needed, and the time and the labor are saved; water in the drinking water troughs is fed into the water tank through the water return pipe, and water freezing in the water troughs is avoided.