A system for producing high-quality gas includes a heat carrier hoist, a coke feeder, a heat carrier heating furnace, a gas mixer, a high-temperature induced draft fan, a heat carrier storage tank, a dryer, a hopper, a concentrating solar collection pyrolysis-gasification reactor having a double-tube structure, a three-phase separator and a coke collecting bin. The system may use an adjustable concentrating solar collection technology in combination with a heat carrier circulation heating process, so as to effectively solve heat requirements of the waste pyrolysis and gasification process, reduce the waste material consumption caused by energy supply, and improve the effective utilization of raw materials.