Pasteurization-based sterilization constant-temperature water heating equipment

The invention discloses pasteurization-based sterilization constant-temperature water heating equipment, comprising a first heat exchanger for increasing water temperature to be between 70 DEG C and 90 DEG C to realize a pasteurization function, a second heat exchanger for converting hot water passing through the first heat exchanger into domestic water with required temperature, and a sterilization kettle for hot water storage, wherein first PID temperature control devices for temperature adjustment are mounted on a first flow pass and a second flow pass, a second PID temperature control device for temperature adjustment is mounted on a fourth flow pass, a water outlet of the second flow pass is connected with a water inlet of the fourth flow pass after passing through the sterilization kettle via a pipeline, a water inlet of the fourth flow pass is further provided with a three way control valve, and a water inlet of the first flow pass is provided with a two way control valve. Firstly, normal temperature water is heated up and pasteurization is performed, and then the water is cooled to reach the use temperature of the domestic water, so that the safety, health and comfort of the domestic water are well ensured.