The numerical simulation model of mechanical oil expression from vegetable oil was developed. It was solved by using of combining finite difference with finite element. The displacement experiment for extracted sesame was used to validate the model. As an applied example, the predictions of pore-fluid pressure dissipation and distribution were carried out. The predicted values of displacement conformed to the measured values well. The pore-fluid pressure decreased with increasing pressing time. The pore-fluid pressure dissipation for the case of double surface seepage was faster than for the case of single surface under the same pressing pressure. The pore-fluid pressure distribution would become uniform with pressing time, and become nonuniform with pressing pressure. And the pore-fluid pressure distributions for the case of double surface seepage were generally more uniform than for the case of single surface.