Display omitted •Pruney fingers-inspired highly stretchable and conductive fibers are developed.•Robust and isotropic wrinkles are constructed on fiber surfaces in a scalable strategy.•Robust interfaces between core-sheath are developed via an in-situ polymerization.•Isotropic surface wrinkles are conducive for high sensitivities in piezoresistive fibers.•Smart gloves fabricated by the piezoresistive fibers have a good application prospect. Scalable construction of robust and isotropic wrinkles on fiber surface is crucial for the development of highly sensitive piezoresistive fibers, which still remains a challenge. Herein, inspired by the typical morphology and formation of pruney fingers, we develop a novel core–shell “pruney fiber” with both isotropic wrinkles and robust interfaces via a scalable and facile fabrication strategy. Briefly, the robust isotropic wrinkles are constructed through the core thermoplastic polyurethane (TPU) molecular chain’s constriction and the sheath pyrrole monomer’ synergistic interfacial polymerization. As a result, the robust interfaces enable the pruney fiber high stabilities under a remark stretchability (200%). Two as-prepared pruney fibers are overlapped vertically for piezoresistive sensing. Owe to the interlocking of the surface isotropic wrinkles, the piezoresistive fibers show high sensitivity (0.15 kPa−1), fast response time (47 ms), low detection limit (0.2 g), and high stability. For practical applications, the piezoresistive fibers can be easily weaved and integrated into a smart glove for wearable sensors and human–machine interfaces (HMI). At last, the novel structure and its unique scalable developing process would pave a new way in stable surface structure engineering on variable surface in the future.