In order to improve the service life of backup bearing in four high rolling mill, the profitable experiments are carried on by improving the bearing structural design, strengthening seal, changing the working period of the roll and repairing the bearing to utilization.

This article introduced some problem of leveller backup roll bearings of Cross Cutting Shearing Line in the initial period,as well as the impact on production,through the analysis of its own drawbacks and defects,described the basis, methods and economic benefits of reconstruction,pointed out the importance of localization.

The backup roll chock is one of the key and important parts of the rolling mill.