The propagation characteristics of optical vortices in fibers are studied. The wave equations in the optical waveguide based on the Maxwell′s equation are derived, and then the eigen modes of the step index fiber are solved. According to the relationship of the orbital angular momentum (OAM) and linear polarization (LP) modes with the vector modes， the distributions of optical vortices and linear polarization modes in fibers are solved and the advantage of optical vortices in fibers over the LP modes in theory are analyzed. The propagation of the optical vortices in bend fibers is simulated. It is found that the distribution of the optical field has periodic rotating properties. The effects of the fiber′s bending radius and the topological charge on the propagation of optical vortices are researched. The smaller the bending radius is, the greater loss in propagation is produced. The larger the topological charge is, the greater loss in propagation and the shorter rotating period is.