Pd-doped alpha-Bi2O3 nanofibers with Pd contents of 0, 0.25, 0.50, 0.75 and 1.00 at% were synthesized via a simple electrospinning process. The structure and morphology of as-prepared nanofibers were systematically characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), and photoluminescence (PL). The photocatalytic denitrification property of Pd-doped alpha-Bi2O3 nanofibers was tested by removal pyridine in light petroleum employed as the simulative fuel oil. The results showed that Pd was successfully incorporated into alpha-Bi2O3 lattice for the absorption band of alpha-Bi2O3 extended to visible light region. The photocatalytic activity of Pd-doped alpha-Bi2O3 nanofibers containing of 0.50 at% Pd exhibited much higher photodegradation activity than that of sole alpha-Bi2O3 and the pyridine photodegradation process was a pseudo-first-order reaction. The introducing of Pd not only extended the absorption scope of alpha-Bi2O3 but also prevented the recombination of photoexicited electron-hole (e(+)-h(+)) pairs. The radical-trapping experiments revealed that the dominant contribution for pyridine photodegradation was h(+) and the mechanism for photocatalytic degradation of pyridine over Pd-doped alpha-Bi2O3 nanofibers under visible light was proposed.