The utility model belongs to the technical field of the transmission, a roller is disclosed, include: bearing frame and the axle that links to each other are with it fixed epaxial barrel and cover are in the section of thick bamboo skin of barrel surface, section of thick bamboo skin comprises the piece section of thick bamboo skin that the polylith stands separately, fixes on the barrel, wherein, piece section of thick bamboo skin with one side of barrel contact sets up extension structure, fixes on the barrel, set up on the barrel with the card that extension structure suited concreties and constructs, fixed locking extension structure. The utility model provides a barrel has promoted section of thick bamboo skin and has changed efficiency, fixed reliability and the utilization ratio of resource.