The concept of the supercritical CO2 (S-CO2) power cycle has been widely proved to be effective by several small scale test loops. However, more specific system layout for fossil-fired power generation and key components design assessment is still imperative to demonstrate the technology feasibility of commercial scale utility. The S-CO2 power cycle must be optimized to deal with fossil-fired system integration constraints. In the present study the technology adaption of S-CO2 power cycle for fossil-fired power plant has been evaluated in terms of both the whole thermodynamic cycle layout and the preliminary assessment of key components. The design considerations and selections of key parameters such as turbine inlet parameters, compressor inlet parameters and split flow ratios were analyzed by a self-developed code for the purpose of optimization design of a 5 MW fossil-based S-CO2 pilot test loop. The proposed recompression and reheat cycle with two split ratios tailored for fossil-fired power plants can achieve 33.49% net efficiency. As a first step to the final recompression cycle, the design of simple recuperated and reheat cycle after carefully considerations of the specific design assessment of core components such as boiler, turbines, compressor and compact heat exchangers has been accomplished and currently under construction. (C) 2019 Elsevier Ltd. All rights reserved.