System and method for recovering waste heat of high-temperature and high-pressure steam in steam boiler

The invention provides a system for recovering waste heat of high-temperature and high-pressure steam in a steam boiler. The system comprises a boiler body, a high-temperature flue gas outlet and a high-temperature steam outlet are formed in the boiler body, and the high-temperature flue gas outlet is connected with a high-temperature flue gas flow channel. The high-temperature steam outlet is connected with at least three steam flow channels. A first steam flow channel, a second steam flow channel and a third steam flow channel are included. A first temperature difference power generation device, a soft water preheating device, a flue gas purification device, a deaerator, an oxygen content detection unit, a first temperature detection unit, a second temperature difference power generation device, a second temperature detection unit and a steam mixing unit are further included. According to the system for recovering the waste heat of the high-temperature and high-pressure steam in the steam boiler, the waste