Objective To analyze the MRI findings of stress urinary incontinence (SUI) in female. Methods The clinical data of 32 female patients with SUI in the hospital were analyzed retrospectively. They were included into the observation group and were treated by transobturator supraubc arch sling. Another 20 patients without SUI were included in the control group. All subjects were examined by MRI, and the morphological changes of the urethral sphincter in the two groups were recorded. The MRI test was performed after 1 week of treatment. The changes of urethral sphincter, posterior urethra-vesical angle and urethral inclination angle were analyzed, and the incidence rate of bladder funnel was analyzed statistically. Results The resting-state thickness of external sphincter of the middle urethra and urethral length in the observation group were significantly smaller than those in the control group [(2.24±0.45)mm, (2.71±0.41)cm vs (2.73±0.56) mm, (2.96±0.47) cm] (P<0.05). There was no statistically significant difference in functional urethral length between the two groups under breath holding state and forcing state (P<0.05). The posterior urethra-vesical angle and urethral inclination angle in the observation group were significantly larger than those in the control group under breath holding state and forcing state (P<0.05). There were 18 cases of positive bladder funnel in the observation group, and they were more obvious under the breath holding state. After operation, there was no significant difference between the two groups in the indexes (P<0.05). Conclusion MRI can reflect the changes of urethral support structure and urethral mobility in patients with SUI.