The rapid progress in Internet of Things (IoT), artificial intelligence (AI) and robotics technology has significantly intensified demand for multifunctional sensors. Nevertheless, achieving simultaneous integration of high sensitivity, versatile functionality and mechanical robustness in a single sensor device remains a substantial technical challenge. Herein, inspired by the hierarchical architecture of human skin, a Janus-structured electronic skin (e-skin) based on micro-nano fiber membranes was designed through a simple processing strategy integrating thermoplastic polyurethane (TPU), carbon black (CB), and polypyrrole (PPy). Due to the synergistic effect of microfiber layer and the nanofiber layer at different scale, the e-skin features extremely high strain sensitivity (gauge factor = 15,684.11), wide sensing range (0.1%–400% strain) and excellent working stability, enabling precise monitoring of angle variations, shape deformation of objects and complex human movements. Moreover, by leveraging the intrinsic sensitivity of CB and PPy, the e-skin also demonstrates multi-modal sensing capabilities in terms of humidity and volatile organic compound (acetone, ethanol, cyclohexane, etc.). Finally, we developed a humidity-monitoring platform capable of detecting hazardous chemicals, offering promising applications in industrial safety early-warning systems and precision environmental monitoring.