The correlation between the dielectric properties of diesel and corrected grinding spot diameter was studied by adding different amount of antiwear agent in hydrofined diesel.It is found that the dielectric constant and the corrected grinding spot diameter has the best correlation.By fitting the data of dielectric constant with the data of corrected grinding spot diameter,a fast prediction model of diesel lubricity based on the dielectric properties was established.Through the comparison between the calculation values of the model and the measured values of the diesel with different antiwear agents,it is found that the results are very consistent and meet the repeatability requirements.Therefore,it is possible to predict the corrected grinding spot diameter of diesel oil by measuring the dielectric constant of diesel.