In this paper, one-dimensional PAN-Bi2O2CO3–BiOI photocatalytic nanofibers were prepared using flexible PAN nanofibers as carriers. Bi2O2CO3 was first grown on the surface of PAN nanofibers, and then BiOI was loaded on Bi2O2CO3 by ion exchange method. The characterization results showed that PAN-Bi2O2CO3–BiOI nanofibers have a diameter of about 210 nm and regular fiber morphology. The results of UV–Vis diffuse reflectance spectroscopy, XRD and XPS showed that Bi2O2CO3–BiOI composed of granular semiconductor nano heterostructures with high specific surface area were uniformly loaded on the surface of PAN fiber. The photocatalytic degradation experiment of the material showed high visible light photocatalytic activity. The preparation of Bi2O2CO3–BiOI heterojunction improved the photoelectron hole separation efficiency of BiOI under visible light. PAN-Bi2O2CO3–BiOI fibers showed high photocatalytic degradation efficiency for rhodamine B. The degradation efficiency was more than 95% within 120 min irradiation. Free radical trapping experiments showed photocatalysts mainly produced O2−,·OH and h+, which played a major role in photocatalysis.