In this study, the solar thermochemical reactor performance for CO2 utilization into synthesis gas (H2 + CO) based on CH4 reforming process was investigated in the context of carbon capture and uti-lization (CCU) technologies. The P1 radiation heat transfer model is adopted to establish the heat and mass transfer model coupled with thermochemical reaction kinetics. The reactor thermal behavior with direct heat transfer between gaseous reactant and products evolution and the effects of different struc-tural parameters were evaluated. It was found that the reactor has the potential to utilize by ～60% of CO2 captured with 40% of CH4 co-fed into syngas (72.9% of H2 and 27.1% of CO) at 741.31 kW/m 2 of inci-dent radiation heat flux. However, the solar irradiance heat flux and temperature distribution were found to significantly affect the reactant species conversion efficiency and syngas production. The chemical re-action is mainly driven by the thermal energy and higher species conversion into syngas was observed when the temperature distribution at the inner cavity of the reactor was more uniform. Designed a solar thermochemical reactor able to volumetric store concentrated irradiance could highly improve CCU tech-nologies for producing energy-rich chemicals. Besides, the mixture gas inlet velocity, operating pressure and CO2 /CH4 feeding ratio were crucial to determining the efficiency of CO2 utilization to solar fuels. Cat-alytic CO2 -reforming of CH4 to chemical energy is a promising strategy for an efficient utilization of CO2 as a renewable carbon source.