Abstract: In order to study the accuracy of products materials prediction in rolling process, and based on the intersected idea raised by M.Torres due to the uneven stress in the roller surface, the grinding and comminution model of roller press is deeply investigated.The on-site tests are carried out by adopting the equipment in Luanxian crushing plant, and the test data is analyzed.After that, MATLAB software is used to fit the selection function and breakage function model to ascertain all parameters that affect the products granularity of roller press.Then an appropriate selection and breakage function model is obtained.After the axial intersection of roller press, the corresponding model parameters are gained according to the experimental data.