The eight-link mechanism reformed from mechanical press based on work principle was split into two-level mechanism for convenience of calculation. The motion relationship of the mechanism was solved by analytical method.After getting the motion relationship, the force analysis was carried on for the most critical guide pin on the basis of dAlembert principle by Matlab, then the minimum section area of the guide pin which was able to bear the work force  was got; at the same time, the model of the press was built by Pro/E, and was imported into Adams software to make force analysis of the guide pin, the correctness of the above theoretical analysis method was further verified．This result can afford theoretic basis for the production of mechanical press.