The load distribution model and isothermal elastic flow lubrication model of the main drive bearing were established based on the actual working conditions of a 6 m shield machine and its main drive bearing,and the load forces under each working condition were obtained,and the influence of geometric modification on the elastic flow lubrication of the shield machine main bearing was analyzed.The results show that judging from the perspective of elastic lubrication,there is an optimization interval in the convex metric of the roller busbar and the radius of the end part corner,which significantly reduces the oil film pressure at the maximum roller load and reduces the edge effect.Geometrically modified rollers have significantly better lubricating properties than straight busbar rollers.Moreover,the modified roller is self-adaptability when the working conditions change,but there is still excessive oil film pressure and low oil film thickness under the limit working conditions.So when the limit working time accounts for a relatively large proportion,the roller convex metric should be appropriately increased.In summary,it can be seen that the lubrication performance of the main drive bearing of the shield machine can be significantly improved by reasonably selecting the geometrically modified roller parameters.