In　this　paper,　specific　exergy　consumption　was　put　forward　to　evaluate　the　thermo-economy　for　the　CO2　capture　system　of　a　power　plant.　Firstly,　specific　exergy　consumption　of　the　regeneration　can　directly　reflect　the　energy　consumption　level　of　the　technology　and　equipments　of　the　regeneration　process　of　CO2　capture　system.　Secondly,　specific　exergy　consumption　of　the　extracted　steam,　which　is　a　comprehensive　evaluating　parameter,　can　reasonably　and　comprehensively　assess　the　degree　of　perfection　of　steam　energy　utilization　process　of　the　CO2　capture　system.　Finally,　exergy　efficiency　is　introduced　to　evaluate　the　effective　degree　of　the　available　energy　utilization　during　the　temperature　reduction　process　of　the　extracted　steam.