System and method for producing fuel chemicals by conducting solar high temperature thermal coupling on methane

The invention provides a system and method for producing fuel chemicals by conducting solar high-temperature thermal-coupling on methane. The method includes the steps of introducing CO2-enriched gasinto a first high-temperature thermochemical reactor, carrying out a thermochemical decomposition reaction to produce a gas mixture of CO and CO2 and first oxygen under irradiation of first sunlight,and making the gas mixture of CO and CO2 sequentially pass a first temperature reducing device and a CO2 removal device to become CO-enriched gas; introducing water vapor into a second high-temperature thermochemical reactor, carrying out a thermochemical decomposition reaction to produce a gas mixture of water vapor and H2 and second oxygen under irradiation of second sunlight, and making the gasmixture of water vapor and H2 sequentially pass a second temperature reducing device and a dewatering device to become H2-enriched gas; after mixing methane-enriched gas with the first oxygen and thesecond oxygen, carrying out a reaction in a methane partial-oxidation reactor to produce synthesis gas; mixing the synthesis gas, the CO-enriched gas and the H2-enriched gas to be introduced into a fuel chemical synthesis tower for reacting to obtain the fuel chemicals.