Objective To explore the application of magnetic resonance imaging (MRI) in the early evaluation of postpartum pelvic floor dysfunction. Methods A total of 80 cases of patients with postpartum pelvic floor dysfunction who were admitted to the hospital from March 2016 to March 2018 were selected as observation group. Another 80 cases of women with normal postpartum pelvic floor function at the same period were selected as control group. The two groups were given MRI scan. The results of transverse, sagittal and coronal images at static state and dynamic state were compared between the two groups. Results Under the static and dynamic MRI scans, the areas of illiococcygeous, pubococcygeous and puborectalis in observation group were smaller than those in control group (P<0.05). In observation group, the width of transverse levator ani fissure, LH line (the link of sagittal pubic symphysis to posterior border of anorectal junction), M line ( the perpendicular distance between right rectal posterior puborectal muscle attachment point to the link of lower edge of pubic symphysis and the 1-2 gap of terminal caudal vertebra), levator plate angle (LPA) and iliococcygeal angle (ICA) were significantly greater than those in control group (P<0.05). The iliac coccygeal muscle thickness (ICT) in observation group was significantly lower than that in control group (P<0.05). Conclusion MRI can show the pelvic floor function and morphological changes in early postpartum period, and it plays an important role in the early evaluation of postpartum pelvic floor dysfunction.