The introduction of orbital angular momentum (OAM) enriches the modulation dimension in the field of optical communication and provides a new idea for finding a more efficient and fast communication way.The nature of the OAM carried by partially coherent twisted beams is more complex than that carried by conventional vortex beams with vortex phases.In view of the OAM of elliptical multi-Gaussian correlated twisted beams transmitted in the gradient-index (GRIN) fiber,based on the ABCD optical transmission matrix of GRIN fiber,this paper investigates the spectral intensity and OMA variation characteristics of the light beam transmitted in it.The results show that the intensity,OAM flux density and normalized OAM flux density vary periodically during fiber transmission.The modulation of the correlation structure and the twisted factor can not only change the distribution of the beam OAM flux density,but also modulate the OAM carried by a single photon.The research in this paper helps to enrich the theoretical results of partial coherent twisted beam transmission in GRIN fibers,which has potential applications in fiber optic communication.