The present disclosure involves occasions where precise two-dimensional motion takes place, and is applicable to XY motion stages for precise displacement compensation. The present disclosure particularly involves a stiffness-frequency adjustable XY micromotion stage based on stress stiffening, which includes X-direction and Y-direction motion sub-stages and corresponding drivers and a micromotion working table. The micromotion stage uses membrane sets that have tension levels thereof adjusted by bolts as a flexible hinge, so as to achieve independent adjustment of the vibration frequency of the XY micromotion stage. The present disclosure implements the foregoing configuration based on prestressed membrane, so the frequency is adjustable. The inherent frequency of the micromotion stage can be adjusted before or during operation according to various working conditions and driving frequency. The two feed motion direction are perpendicular so as to prevent the micromotion working table from coupling during two-dimensional motion.