The production and processing precision of roller accessories mainly refers to the concentricity of the steel shell and the inner hole at both ends of the rollers, as well as the processing precision of the axial dimensions of the various parts. If the concentricity is too poor, which will cause the rolling bearing to lock up , increase the resistance, and shorten the service life. If the axial dimensional inaccuracy of the parts are too large, a large axial clearance will be formed, which will cause axial displacement, destroying lubrication and sealing; if the installation quality is not good, it will occur run-off, sticking and worsening wear, greatly shortening the service life of the rollers. How to reasonably arrange the rollers, design an appropriate spacing between the idlers, to reduce the number of rollers used,reduce the overall machine price, reduce investment, operating and maintenance costs, to improve economic benefits, the processing technology of the rollers is an important aspect .