Inspired by the phase change materials (PCMs) based microcapsules, green phase change nanofibers mats with cores-heath structure based on paraffin wax emulsion (PWE) and polyvinyl alcohol (PVA) for thermal energy storage (TES) is obtained by coaxial electrospinning approach. The PWE could be encapsulated by PVA, simultaneously addressing the leakage issue effectively. In addition, the melting enthalpy (Delta H-m) increased from 3.16 J/g to 48.35 J/g as the core speed rate (R-core) increased from 0.1 to 2.0 it/min, indicating higher R-core can induce higher PWE encapsulation efficiency. Finally, the core-sheath structure PWE@PVA nanofibers mats have high Delta H-m of 48.25 J/g and freezing enthalpy (Delta H-c) of -47.75 J/g. Furthermore, only slightly decreasing tendency on the enthalpy can be observed after 500 heating-cooling cycles, demonstrating good TES stability and practicability of the as-prepared PWE@PVA nanofibers mats. Hence, this study offers new idea for the fabrication method of green PCMs.