Compared with other groups, the combination group showed shorter claw extending reflex recovery time (P<0.05). Significant differences were found between the combination group and other groups in nerve conduction velocity, the remnant rate of gastrocnemius wet weight, the diameter and section area of gastrocnemius cells (P<0.05). The nerve fibers through the anastomotic site were significantly increased, with consistent thickness and arrangement and less neurodegeneration when observed 12 weeks after operation. In conclusion, the modified chitosan combined with methylprednisolone could significantly promote the sciatic nerve repair.