The utility model discloses an energy-saving electric heater which comprises an upper water bag, a lower water bag, and multiple radiating pipes which connect the upper water bag and the lower water bag together and are arranged in parallel. The lower water bag is internally and fixedly provided with a heating rod; one end of the heating rod is connected with a power source while the other end thereof extends to the inner part of the lower water bag. In the technical scheme, the radiating pipes can be relatively thin and the distance among the radiating pipe can be big, so that water is saved; meanwhile, the heating rod heats from the downside to the upside, so that the thermal cycling force is high.