As　China　continues　to　adjust　its　energy　structure　in　order　to　address　energy　security　and　environmental　crises,　changes　in　centralized　heating　technology　and　energy　saving　are　gradually　being　promoted.　Flue　gas　waste　heat　recovery　from　traditional　gas　boilers　has　the　potential　to　play　a　significant　role　in　the　promotion　of　low-carbon　heating,　energy　saving,　and　emission　reduction.　This　study　took　the　Beijing　Baoneng　Heating　Plant　as　its　research　object.　We　designed　a　flue　gas　deep-condensation　waste　heat　recovery　system　based　on　the　combination　of　absorption　heat　pump　technology　and　stepped　waste　heat　recovery　technology.　We　determined　that　40　degrees　C　is　the　target　temperature　for　flue　gas:　At　this　point,　the　condensate　in　the　flue　gas　is　precipitated　by　approximately　60%.　This　results　in　a　12.18%　efficiency　improvement　in　the　boiler.　Subsequently,　experimentation　demonstrated　that　the　recovered　flue　gas　heat　was　able　to　fulfill　the　heating　requirements　of　the　Baoneng　plant　and　that　it　was　able　to　enhance　the　heating　capacity　of　the　heat　source　plant　by　utilizing　the　flue　gas　waste　heat　without　increasing　energy　consumption.　This　represents　a　mutually　beneficial　scenario　for　environmental　and　economic　considerations.