Abstract: The supercritical carbon dioxide recompression Brayton cycle is a highly efficient and compact energy conversion. When analyzing the characteristics of a cycle, many studies often assume that the efficiencies of a compressor and a turbine are constant, and this assumption is very different from the actual situation. In this paper, a supercritical carbon dioxide recompression Brayton cycle model was established with MODELICA. Real performance maps of turbine and compressor were added. Simulation results indicate that when the cycle is in the off-design condition, the proper control of the input power and the circulation flow can effectively regulate the cycle output power and the exergy efficiency.