Fiber-based structured light fields, as an important branch of light field modulation, have gradually attracted much attention of researchers. First, based on the fiber vector mode theory, the generation mechanism of fiber-based structured light fields with spatial polarization/phase singularity is discussed. Then, the generation methods of fiber-based structured light fields, such as long-period fiber grating coupling method, fiber end face microstructure method, and orbital angular momentum conversion method, are introduced. Finally, some typical applications of fiber-based structured light fields in super-resolution imaging, vortex light communication, plasmonic tip nanofocusing, nonlinear frequency conversion and so on are presented.