The paper studies the optimization design of rolling deformation schedule on plate mill. In order to ensure to play equipment ability full and control the precision of flatness, optimization mathematical model of flatness passes is firstly given. Then, the objective function is formulated in accordance with the actual production conditions, and the flatness constraint conditions are confirmed based on equipment and technical requirements. Finally, GA is applied in the optimization calculation of rolling schedule and a lot of simulation experiments are conducted with actual data. Analysis and comparison of optimized schedule with the existing schedule were offered. It is seen that the performance of the optimal rolling schedule is satisfactory and promising and the design is feasible and promising.