▎ 摘　　要

NOVELTY - Lubricating oil additive comprises surface modified graphene oxide containing bile acid salt or its derivative, where amount of urface modified graphene oxide containing bile acid salt or its derivative in lubricating oil is 0.01-0.9 wt.%. USE - The additives is useful in lubricating oil (claimed). ADVANTAGE - The additive has simple preparation method, high repition rate and excellent dispersibility, is suitable for large scale industrial production, and can effectively increases friction resistance of lubricating oil. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) lubricating oil based on surface modified graphene oxide comprising lubricating oil additive based on surface modified graphene oxide; (2) preparing lubricating oil additive comprising either preparing graphene oxide, then dispersing mixture in organic solvent to obtain graphite oxide dilute solution, then adding bile acid salt or its derivatives, and then reacting to obtain final product, or dispersing preparing graphene oxide, dispersing in water to prepare graphene oxide diluted solution and then bile acid or its derivatives, heating to 60-80 degrees C and reacting to obtain final product; and (3) preparing lubricating oil comprising adding lubricating oil additive based on surface modified graphene oxide material into lubricating oil, and uniformly mixing to obtain final product, where the amount of lubricating oil additive in lubricating oil is 0.01-0.9%, preferably 0.1-0.6%.