Abstract: To improve the accuracy and stability of the flexible positioning platform, a key mechanism of the ultra-high acceleration macro-micro motion platform, the dynamic response of the platform under specific excitations is studied. The flexible positioning platform is subjected to harmonic response analysis using SolidWorks and Ansys Workbench. The modal superposition method is adopted to obtain the inherent characteristics of the flexible positioning platform. In the working conditions, the piezoelectric actuator is used to provide displacement positioning for the micro-motion platform, and the displacement-frequency response curve is obtained. Through the peak response nephogram, the hinge of the flexible positioning platform is determined as the dangerous area under the actual load. Finally, the response surface optimization method is utilized to optimize the design of the dangerous area of the flexible positioning platform, and the optimized model is verified. The research data shows that the first-order natural frequency of the flexible positioning platform is increased by 3.7%, and the maximum amplitude responses in the X-axis, Y-axis, and Z-axis directions are respectively decreased. The overall structure becomes more stable, providing valuable reference for the structural design of the positioning platform with flexible hinges and the response research under excitations.