The geometrical structure of solar receiver and reactor directly influences the heat transfer characteristics and chemical reaction process,The use of optical characteristics to produce high intensity radiation flux is a common method of building high temperature. In this research, a high temperature reactor based on parabolic dish solar receiver is constructed, which is divided into preheating zone and porous reaction zone. A three-dimensional numerical model of parabolic dish solar receiver and reactor is built by COMSOL Metaphysics software to analyze the distribution law of heat flux in coke plane, the velocity and temperature distribution of reactor under typical operating conditions (DNI=800W/m2), and the influence of reaction fluid inlet velocity and DNI on heat transfer characteristics of reactor. The results will help to explore the efficient use of solar energy and high temperature chemical reactions.