Based on the Collins diffraction integral formula,the evolutionary of phase singularities in vortex cosine-hyperbolic-Gaussian beam (vCHGB) propagating in graded-index (GRIN) fibers is studied. The analytical expression of electric field distribution for vCHGB propagating in the GRIN fibers is derived,and the effects of beam modulation parameters and topological charges on beam propagation charactetistics are analyzed with numerical simulation.The results show that when the topological charges exceed two,the splitting behavior of phase singularities varies with different topological charges.During propagation,the beam′s intensity distribution, phase profile, and the spacing between split phase singularities and the origin all exhibit periodic variations with increasing transmission distance.These findings have potential applications in high-capacity,high-speed optical fiber communication systems.