【S】objective:To discuss the application value of perineal four dimensional ultrasound imaging for postpartum pelvic floor dysfunction(PFD).Methods: 84 puerpera with postpartum PFD were selected as group A from Match 2016 to Match in our Hospital,80 puerpera with no postpartum PFD were selected as group B at the same time,all puerperas were given perineal four dimensional ultrasound imaging under the quiet, Valsalva (breath-holding) motion.Results:The levator hiatal area(LHA),levator hiatal lateral pathway(LHLP),levator hiatal anteroposterior pathway(LHAP) and left, righ levatort thickness(LT) ,levels of group A were significantly higher than those of group B, the difference was statistically significant (P < 0.05).The diagnosis of postpartum perineal PFD sensitivity, specific and accuracy by perineal four dimensional ultrasound imaging were 95.24%,92.50%,95.24%,when it compared with the actual result, there was no statistically significant difference (P > 0.05).Conclusions:The maternal dLHAP、LHLR、LHA and left, righ LT are associated with postpartum PFD occurs under the quiet, Valsalva (breath-holding) motion,the diaphragmatic hiatus and anal muscle morphological features are checked by perineal four dimensional ultrasound imaging,which is conducive to accurately identify postpartum PFD happen as early as possible.