Fabricating large-scale flexible perovskite oxide films that maintain structural integrity and stability under extreme conditions is crucial to innovative device applications. Here, a novel flexible film fabrication strategy based on controllable thermal-mechanical coupling is developed. Specifically, a dynamic warpage angle is constructed by leveraging the non-uniform stress field induced by controllable thermal gradient of the flexible substrate. The mass transfer pathways of the sacrificial layer's water-soluble reaction are optimized, enabling damage-free exfoliation of large-area single-crystal oxide films. This work resolves the long-standing issues of cracks and wrinkles during water-assisted film exfoliation. The resulting flexible films exhibit exceptional mechanical flexibility and functional stability, and their adaptability to extreme environments is significantly enhanced compared to the films with PDMS as the flexible substrate. This work provides a universal strategy for integrating high-performance single-crystal oxides into flexible electronics that operate far beyond conventional limits.