According to one embodiment, a carbon-dioxide-recovery-type steam power generation system comprises a boiler that generates steam and an exhaust gas, an absorption tower that allows carbon dioxide contained in the exhaust gas to be absorbed in an absorption liquid, a regeneration tower that discharges a carbon dioxide gas from the absorption liquid supplied from the absorption tower, a reboiler that heats the absorption liquid of the regeneration tower, a turbine that is rotationally driven by the steam, a first condenser, a second condenser, and a desuperheater. The first condenser generates condensate by cooling steam exhausted from the turbine. The second condenser condenses the carbon dioxide gas while using a part of the condensate as cooling water, and generates hot water.The desuperheater lowers the temperature of the steam exhausted from the turbine by spraying the hot water, and supplies the steam at lowered temperature to the reboiler.