Hot water energy-saving metering system

The invention discloses a hot water energy-saving metering system which comprises a water heater, an information acquisition module, a controller, an external power source and water consumption equipment, the output end of the water heater is fixedly connected with the water consumption equipment through a pipeline, and the water heater is electrically connected with the external power source. A controller and an information acquisition module are electrically connected between the water heater and the external power supply in sequence; when water is supplemented to the water tank, the information acquisition module acquires the water inlet temperature value and the water inlet flow, and the water inlet temperature and the water inlet flow are calculated according to an algorithm; when water is used, the information collecting module counts the water outlet temperature value and the water outlet flow, the water outlet temperature, the water outlet flow, the zero point of each day and the heat energy value of