The utility model provides an exhaust -heat boiler afterbody heat exchanger system, including oxygen -eliminating device and condenser, the condenser is equipped with condensate pump, and this systemincludes still that low pressure economizer, the hot water heat exchanger of flue gas and bromine are cold quick -witted, low pressure economizer's the end of intaking is connected through a valve tocondensate pump's play water end (W. E. ), and low pressure economizer's play water end (W. E. ) is through a valve connection oxygen -eliminating device, the end of intaking of the cold machine of bromine is connected through a valve to the hot water heat exchanger's of flue gas play water end (W. E. ), and the play water end (W. E. ) of the cold machine of bromine is through a hot water heat exchanger's of valve connection flue gas the end of intaking, low pressure economizer's the end of intaking is connected to the hot water heat exchanger's of flue gas play water end (W. E. ) through a valve, the hot water heat exchanger's of flue gas the end of intaking is connected to condensate pump's play water end (W. E. ) through a valve. The utility model discloses not only be favorable to thesafe operation of unit, also can effectively utilize the flue gas waste heat simultaneously, improve energy utilization, improve the economic nature of power plant.