<p>Cells live in a multiphysics-coupled microenvironment in vivo, in which electric fields (EFs) and mechanical cues are the most essential induction signals. The regulatory effects of EFs and stiffness on cells have been independently demonstrated. However, how cells respond to electromechanical coupling cues remains mysterious. In this study, an electro-stiffness-coupled chip system was designed and fabricated, freely integrating and precisely controlling EF strength and the mechanical stiffness applied to cells across the physiological spectrum. Utilizing the innovative bioreactor, it was observed that electromechanical coupling stimulations can shape cancer cell morphology and cytoskeleton into a unique anteroposterior polarization state and orient cancer cell migration in a voltage-dependent manner through cytoskeleton-associated mechanisms. Moreover, the mechanical stiffness regulated cancer cell susceptibility to EFs, and the orientation effect of EFs on cells required a stiffness threshold. Furthermore, transforming growth factor-β1 suppressed the orientation of cancer cells induced by electromechanical coupling signals and showed a splitting effect on the directionality and velocity of cancer cell migration, indicating a comprehensive cross-talk of biochemical–electromechanical signals. Together with the dual-physical bioreactor we designed, these findings provide a robust and convenient platform for exploring cellular responses to electro-stiffness coupling signals, reveal the biophysical mechanisms of cell polarization and migration from the perspective of electromechanical coupling, and lay a promising foundation for biophysical-based cell manipulation and therapeutic interventions.</p>