The utility model relates to a cylindrical piece coating supporting device and belongs to the field of coating assistance. The support device comprises an operating rack, a transmission motor, support shafts, positioning brackets and toothed belts, wherein two groups of positioning brackets are vertically fixed on the upper surface of the operating rack; shaft connecting holes which are distributed horizontally are formed in each group of the positioning brackets; a support shaft which is perpendicular to the positioning bracket is connected into each shaft connecting hole through a bearing; all support shafts of the two groups of the positioning brackets are arranged in a front-and-back symmetry manner; transmission rollers are mounted on the outer wall, on the outer sides of the two groups of the positioning brackets, of the support shafts on one group of the positioning brackets; the transmission rollers are connected with the transmission motor fixed on the working rack through the toothed belts. By adopting the device, the problem of a coating process for a cylindrical piece is solved, and the coating quality and the production efficiency of a coating are improved.