The increase of multifidus muscle fat infiltration will affect the postoperative rehabilitation of patients with lumbar spine surgery. In this study, reasons for fat infiltration on both sides of multifidus muscles were analyzed retrospectively. Through Priffman grading evaluating the intervertebral disc and Kader grading for fat infiltration, a retrospective analysis was conducted on 453 cases of intervertebral discs images. In our study, nerve root compression was found to be correlated with degree of multifidus muscle fat infiltration. This correlation support the hyposis that nerve root compression would result in an increase in the adiposity of multifarious muscles.