The invention relates to a solar high-temperature thermochemical coupling phase-change reactor. The solar high-temperature thermochemical coupling phase-change reactor comprises a CPC (Card Programmed Calculator) secondary optical collector, a quartz glass window, a heat plate, a heat pipe and a cylinder body, wherein a main body is coupled by the heat plate and the heat pipe, the heat plate is positioned at a photothermal conversion side, the heat pipe extending out of the heat plate is positioned at a reaction side, and the heat plate and the heat pipe are communicated into an integer; a heat absorption cavity is formed by the quartz glass window, the heat plate positioned at a heat absorption side and the inner wall of the cylinder body; and a reaction cavity is formed by the heat plate positioned at the reaction side, the heat pipe and the cylinder body. Sunlight is converged and then shines on the heat absorption side of the heat plate, optical energy is converted into heat energy, the heat energy is transferred to an internal working medium through the heat absorption side of the heat plate, the internal working medium transfers heat to the heat plate positioned at the reaction side and the wall surface of the heat pipe through phase-change heat transfer, and a reactant absorbs the heat emitted from the wall surface for chemical reaction. The solar high-temperature thermochemical coupling phase-change reactor can be used for intermediate-high temperature thermal chemical reaction, i.e. the pyrolysis or the reduction of metallic oxides, and the like, prevents the sintering or the damage caused by local overheating of the surface of the heat absorption side, reduces the temperature gradient of the reaction cavity and increase the efficiency and the stability.