A twodimensional micromotion platform was designed with the double parallel flexible hinges and the stiffness of the micromotion platform in each direction was calculated. According to the constraint conditions, a theoretical stiffness mathematical model was established; the sequential quadratic programming(SQP) algorithm was used for the multiobjective optimization of the platform structure, and the mathematical model was solved by MATLAB software; the displacement, stiffness and natural frequency of the optimized platform were simulated and analyzed by using ANSYS software. The theoretical calculations and simulation results show that the micromotion platform has good static and dynamic characteristics.