Abstract In this work, the cascaded supercritical CO 2 system integrated with solar and biomass energy is proposed. The system contains two parts, i.e. the recompression cycle and the simple cycle. The solar receiver or biomass burner replaces the combustor chamber in conventional Brayton cycle. Energy analysis and exergy analysis are implemented to evaluate the feasibility of the proposed system. Under the consideration of the changes of solar irradiations and biomass complementary, the design and off-design thermodynamic performances of the system are numerically studied. Results indicate that the thermal efficiency of total system reaches 40.1%. Owing to the introduction of biomass input in the proposed system, the power generation efficiency is insensitive to solar radiations and times, and thus an efficient and stable utilization approach of solar energy and biomass is achieved at all work conditions. The theoretical results indicate that the cascaded supercritical CO 2 with multi-energies input as a power cycle is a promising option for the efficient utilization of the abundant solar and biomass resources in the Western China.