<p>Polymer-based piezoelectric films can be assembled into piezoelectric nanogenerators (PENGs), which can simultaneously serve as flexible pressure sensors and energy harvesting devices. However, the low piezoelectric output of PENGs is a major limitation for their practical applications. Herein, we propose a coaxial electrospinning strategy to generate a core-shell structured nanofiber film, which could significantly enhance the piezoelectric output compared to the traditional nanofiber film <i>via</i> conventional single-axial electrospinning. Notably, the as-prepared PENGs based on the core-shell structured CsCuCl₃/poly(vinylidene fluoride) (PVDF) nanofiber composite film (2 wt%) produced <i>via</i> coaxial spinneret exhibit a 60% increase in output voltage (increase from 48 V to 75 V) and a 50% increase in short-circuit current (increase from 0.2 µA to 0.3 µA) compared to those prepared using a single-needle spinneret. More interestingly, this enhancement in piezoelectric performance is a universal phenomenon because the coaxial electrospinning process can induce greater polymer chain alignment in the shell layer and lead to increased crystallinity and a higher proportion of the piezoelectric-active <i>β</i>-phase. Owing to their enhanced piezoelectric output and high sensitivity to subtle pressure variations, the resulting PENGs demonstrate promising potential for human-machine interaction applications. This study offers a novel and broadly applicable approach to boost the piezoelectric performance of polymer-based PENGs.</p>