Objective To explore the diagnostic value of pelvic floor ultrasound parameters combined with diastasis recti abdominis (DRA) for postpartum pelvic organ prolapse (POP). Methods A total of 98 postpartum POP patients admitted to our hospital from January 2023 to December 2024 were selected as the POP group, and 90 postpartum non-POP women during the same period were selected as the control group. Basic data, DRA, and pelvic floor ultrasound parameters under different conditions were compared between the two groups. Pearson correlation analysis was used to analyze the correlation between pelvic floor ultrasound indicators, DRA and the severity of POP. Results The proportion of pregnancy history, delivery history and DRA in the POP group were significantly higher than those in the control group. The anterior-posterior diameter of the levator ani hiatus, the area of the levator ani hiatus and the posterior angle of the bladder urethra in the POP group were significantly higher than those in the control group under resting, anal contraction and maximal Valsalva maneuver conditions. The pelvic floor ultrasound indicators of the POP patients, including the anterior-posterior diameter of the levator ani hiatus, the area of the levator ani hiatus and the posterior angle of the bladder urethra, and DRA were positively correlated with the severity of POP. The results of multivariate Logistic regression analysis showed that pregnancy history, delivery history, DRA and pelvic floor ultrasound indicators were independent risk factors for postpartum POP. The ROC curve showed that the AUC and sensitivity of combined predictive probability in diagnosing postpartum POP were superior to those of individual diagnosis of each index and simple parallel diagnosis. Conclusion The combination of pelvic floor ultrasound and DRA can significantly improve the diagnostic efficiency of postpartum POP, providing a reference basis for the clinical diagnosis and treatment of POP.