The invention relates to a gantry-type polishing system which comprises a machine tool base, a headstock, a tailstock box, carrier rollers and a gantry-type polishing device, wherein the headstock is fixedly mounted at one end of the machine tool base; the tailstock box is mounted at the other end of the machine tool base; the headstock and the tailstock box are used for supporting and fixing a workpiece coaxially; the gantry-type polishing device is mounted on the machine tool base in a guiding and sliding manner; gear racks meshed with driving gears at the lower ends of the gantry-type polishing device are horizontally and fixedly mounted in the machine tool base in the same axial direction; the gantry-type polishing device comprises a gate-type framework, a driving structure and a polishing device; the driving device is mounted in the gate-type framework; and a polishing device is coaxially mounted on the side of the gate-type framework. The gantry-type polishing system has the advantages that the structure is simple; the design is scientific; the cost is reduced; the adjusting is convenient; the positioning is accurate; the polishing effect is good; the structures of all parts are reasonable to facilitate maintenance; the production efficiency and the quality can be improved remarkably; the polishing effect is favorable; and the quality of a polished product can be guaranteed efficiently.