Enamel steel solar energy heat-collecting pipe and flat water heater

The invention discloses an enamel steel solar energy heat-collecting pipe and a flat water heater. The enamel steel solar energy heat-collecting pipe comprises a case body, a water inlet pipe and a water outlet pipe. The enamel steel solar energy heat-collecting pipe is characterized in that an enamel steel solar energy heat-collecting pipe is placed in a case body cavity; the front part of the case body is fixedly provided with double-layered tempered coating film vacuum flat glass; a water inlet joint of the enamel steel solar energy heat collecting pipe is connected with the water inlet pipe; and a water outlet joint of the enamel steel solar energy heat-collecting pipe is connected with the water outlet pipe. The enamel steel solar energy heat-collecting pipe possesses excellent heat insulating performance and heat collecting performance; the heat-collecting pipe can be used all the day and without limitations of regions; solar energy heat collection and storage can be integrated, so solar energy heat collection and storage performance can be improved to the largest extent; integration with the building and component-based arrangements can be achieved; pressure-bearing operation is realized; dead water area is avoided; the enamel steel solar energy heat and regular energy can be reliably compensated, so water use stability and comfortableness of the solar energy water heater can be achieved; industrialized production of the heat-collecting pipe can be achieved with simplicity and reliability; and the heat-collecting pipe can be applied to high temperature heat usage fields in a marketing and industrialized way.