The invention discloses a plasma gasification and melting system for solid waste centralized processing, and relates to the technical field of solid waste thermochemical treatment. The system comprises a plasma gasification and melting furnace, a synthesis gas outlet of the plasma gasification and melting furnace is connected with a secondary combustion chamber, a high-temperature smoke outlet ofthe secondary combustion chamber is sequentially connected with a waste heat recycling system and a smoke purifying system, and the synthesis gas outlet of the plasma gasification and melting furnaceis further connected with a reforming chamber, a high-temperature synthesis gas outlet of the reforming chamber is sequentially connected with a heat exchange system and a synthesis gas purifying system. The controlled oxygen combustion technology is adopted in the plasma gasification and melting furnace, the excessive air coefficient of primary air is about 0.3 to 0.5, the dust amount in rough synthesis gas can be effectively reduced, re-generation of toxic and harmful substances of dioxin and furan can be restrained, and the production of flying ash amount can be reduced.