Pure and 0.3, 0.5 and 1 wt% Pt-doped one-dimensional nickel oxide (NiO) nanofibers were successfully synthesized via a simple electrospinning method in combination with subsequent calcinations. X-ray powder diffraction, field-emission scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy were employed to characterize the prepared samples. Planar-type NiO based gas sensors were fabricated and their gas sensing properties were systematically measured towards ethane, an important fault characteristic gas dissolved in transformer oil. It is found that the 1 wt% Pt-doped NiO nanofibers sensor exhibits significantly enhanced ethane gas sensing behaviors in term of lower operating temperature and higher gas response than those of pure, 0.3 and 0.5 wt% Pt-doped NiO sensors. Moreover, it shows an excellent selectivity to potential targeted gases with rapid response-recovery time and long-term stability. Finally, a possible sensing mechanism was further investigated. These results demonstrate the prepared sensor doped with 1 wt% Pt a promising candidate for ethane detection in practice.