The invention relates to an integrated carbon capture carbon dioxide double-Brayton-cycle power generation system. The integrated carbon capture carbon dioxide double-Brayton-cycle power generation system comprises a main cycle, a bottom cycle and a carbon capture system. The main cycle comprises a waste heat exchanger, a precooler, a main compressor, a recompressor, a low-temperature regenerator,a high-temperature regenerator, a high-pressure CO2 turbine, a low-pressure CO2 turbine, a main cycle power generator and a boiler which are connected through a main cycle working medium pipeline. The bottom cycle comprises a CO2 turbine, a second compressor, a second precooler, a first compressor, a bottom cycle power generator and a water-CO2 heat exchanger which are connected through a bottomcycle working medium pipeline. The carbon capture system comprises a reboiler, a storage tank, an overhead condenser, a compressor, a steam-water separator, a condenser, a regeneration tower, an absorption tower, a rich-lean liquor exchanger, a rich liquor pump and a lean liquor pump. Through the integration of the whole system, the waste heat utilization rate of a main cycle power generation system is increased, the source problem of a cycle working medium of a supercritical CO2 Brayton-cycle power generation system and the application problem of captured carbon dioxide are solved, and the CO2 emission reduction cost of power plants is lowered.