Press is one of the main machines in wood-based panel production. Its mechanical design mainly includes calculation of the ridigity and strength of frame, reasonable arrangement of frame in longitudinal direction, calculation of bending moment, tension and compression stresses exerted on upper and lower platens, relation between location of cylinders and ridigity of the upper platen. These calculations involve so many factors, each of which can effect the final result. So we should treat the data by computer so that the best design could be found quickly with no error.