The analysis of motion and dynamics is carried out on the energy-saving injection molding machine.Taking increase the stroke ratio and the amplification of the force

and to decrease the total length of mechanism as objective function

the multi-objective optimization mathematics model is established.A complete optimal design procedure is carried out by using optimal toolbox in Matlab.The correctness of the optimization model is verified by the example and comparison with the optimization results

so a theoretical reference are provided to optimization design for injection mould.