The invention discloses a water heater return water control device and method. By means of the water heater return water control device, it can be ensured that hot water can be utilized as long as thehot water is boiled. The water heater return water control device comprises a first water pipe joint, a data processing control module, a second water pipe joint, a temperature sensor, a first electromagnetic water valve, a second electromagnetic water valve, a circulating water pump, a third electromagnetic water valve, a third water pipe joint and a fourth water pipe joint. The temperature sensor is used for collecting and measuring the water temperature; the electromagnetic water valves are used for preventing water from flowing back; and the data processing control module is used for receiving signals of the temperature sensor and controlling the starting and stopping of the water heater return water control device. The water pipe joints are used for connecting cold and hot water pipes, water utilizing equipment and the water heater return water control device. The water heater return water control device solves the problem of space occupation of three pipelines of an existing hotwater return technology device, the cost is saved, and the water utilization efficiency is improved.