Abstract： Objective To analyze the application of pelvic floor ultrasound combined with pelvic floor muscle strength detection in the evaluation of postpartum pelvic floor function and prediction of pelvic floor dysfunction three years after delivery.Methods A total of 192 women at 42 days postpartum were enrolled,including 85 in the vaginal delivery group and 107 in the cesarean section group.The abnormal rates and levels of the indicators related to pelvic floor muscle strength detection and pelvic floor ultrasound were compared.The patients were followed up for three years,and the incidence of pelvic organ prolapse and stress urinary incontinence were analyzed.Results The results of pelvic floor ultrasound were abnormal in 102 patients(53.13%).The abnormal rate of fatigue of typeⅠmuscle fibers was highest(85.94%)in pelvic floor muscle strength detection.The abnormal rates of bladder neck mobility,bladder posterior angle opening,cystocele,levator ani muscle injury,levator hiatus area,perineal body activity,and vaginal dynamic pressure were significantly higher in the vaginal delivery group than those of the cesarean section group(P<0.05).There were significant between-group differences in the mean values of bladder neck movement,levator hiatus area,distances from the bladder neck to the lower margin of the pubic symphysis and from the ampulla of the rectum to the lower margin of the pubic symphysis during the Valsalva movement,vaginal dynamic pressure,and muscle strength(P<0.05).After the 3-year follow-up,the incidences of pelvic organ prolapse and stress urinary inconti-nence were significantly higher in the vaginal delivery group than in the cesarean section group(P<0.05).In the patients with pelvic floor dysfunction,the results of pelvic floor ultrasound and pelvic floor muscle strength detection were both abnormal at 42 days postpartum.Conclusion The patients with abnormal results of pelvic floor ultrasound and pelvic floor muscle strength detection at 42 days post-partum are more likely to have pelvic floor dysfunction in the future.