Abstract: A numerical model was established by spline curve interpolation method to study the relationship between physico-chemical properties of the cracking products and the operation parameters of throughput and temperature in hydrocracking process. This model was applied to the optimization analysis of a VGO hydrocracking process. The smoke point and freezing point of aviation jet fuel, diesel yield as well as middle distillate selectivity were used as the constraint objects in the optimization to investigate the feasible operation parameter ranges of throughput and reaction temperature. Under the constraint objects, the minimum conversion was calculated by the model to get the operation parameters for high tail oil yield and compared with the experimental data. The comparison shows that the method has a good effectiveness and the data calculated is close to the experimental results.