The utility model discloses a grate waste incineration power generation waste heat utilization system has set gradually over heater, evaporimeter and economizer along the flue gas flow direction of flue gas passageway, the over heater comprises first over heater, second over heater and the third over heater of establishing ties in proper order, be equipped with the protection baffle plate who is used for blockking the flue gas before the over heater, the last hole that supplies the flue gas to pass through that is equipped with of protection baffle plate. The utility model discloses the waste heat utilization system can rationally restrain the production of dioxin in the flue gas, reduces later stage flue gas intractability to cooperate reasonable dust collector, can reduce the volume that the pipeline adheres to the dust, thereby improve the life of pipeline.