g-C3N4/C composite nanofibers were prepared via a combination process of electrospinning, preoxidation and carbonization by using g-C3N4 nanosheets and polyacrylonitrile as raw materials. Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), Raman spectroscopy (Raman) and scanning electron microscopy (SEM) were employed to analyze the structure and morphology of the as-synthesized nanofibers. And UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) was used to assess their visible light response. The results show that the g-C3N4/C composite nanofibers exhibit good photocatalytic degradation activity toward rhodamine B under visible light, which originates from better ability of their partially amorphous carbon matrix to reduce the combination of the photogenerated electron and hole pair. The nanofiber membrane was not embrittled into powers or small flakes during the photocatalytic degradation process under stirring conditions, maintaining its integrity from begin to end. After several recovery and photocatalysis experiments, the membrane still maintained high photodegradation rate. This study reveals that the resulting nanofibers have excellent recycling stability to photodegradate rhodamine B under visible light.