According to the relation curve of wear extent of roller- time, the influencing factors and the changing trend of dimensionless friction coefficient were analyzed. According to the basic principles of tribology, the single grain flour as the research object, the pressure between the rolls of roller mill during grinding, slippage and rolling amount were calculated in order to deduce the wear and tear amount after turn N rotations. A mathematical model of flute depth and surface wear of the roller was established with Buhler MDDK 1000/250 roller mill at IB process section as research object. According to the mathematical model, the relationship among variables was studied with the total wear amount, frontal angle and obtuse angle as independent variables, and the wear extent of flute as dependent variable, which provides a theoretical reference for the study of the wear.