Abstract: Carbon dioxide capture by chemical absorption can effectively reduce the CO2 emissions of coal-fired power plants, but the carbon capture system consumes a lot of steam in the process of CO2 desorption, which reduces the power generation efficiency of the power plant. In order to reduce the impact of carbon capture on power generation efficiency, a carbon capture system with organic Rankine cycle is proposed. A carbon capture process system capturing 1 million tons of CO2 per year was established in Aspen plus, and organic Rankine cycle was used to recover the residual heat of desorption tower exhaust and reboiler condensate. Five organic working materials, RC318, R152a, R600a, R600 and R245fa, were selected to analyze the net power generation and heat absorption, thermal efficiency and exergy efficiency of the organic Rankine cycling system, and the cooling water circulation volume of the integrated system. The results show that the evaporation pressure and flow rate of organic working medium in the integrated system are proportional to the net generating power, but there is a phenomenon where these two factors limit each other. When the evaporation pressure is 3MPa and the flow rate is 188kg/s, the working medium R152a is the maximum net power, up to 7.3899MW, and the increase of cooling water circulation is the smallest, only 3.36%, which can reduce the loss of the power plant by 18.66%.