Objective: To study the ultrasonic quantitative evaluation of pelvic floor characteristics in patients with stress urinary incontinence and the correlation with extracellular matrix remodeling and apoptosis. Methods: Patients with stress urinary incontinence who received surgical treatment in Xuzhou Central Hospital between February 2015 and April 2017 were selected as the SUI group of the research, female healthy volunteers who received physical examination during the same period were selected as the control group A of the research, and patients who received total hysterectomy for benign disease during the same period were selected as the control group B of the research. The ultrasound parameters of pelvic floor characteristics of SUI group and control group A were determined before surgery, and the contents of collagen metabolism indexes, extracellular matrix metabolism indexes and apoptosis genes of SUI group and control group B were determined after surgery. Results: Pelvic floor ultrasound parameters BND, R-RVA, V-RVA and UR levels of SUI group were higher than those of control group A; Col-I and Col-II contents as well as Fibulin-5, LOX and LOXL1 mRNA expression in pelvic floor tissue of SUI group were significantly lower than those of control group B and negatively correlated with pelvic ultrasound parameter BND while ICTP content as well as Calpain1, Calpain2, Caspase-3, LC3-II and Beclin-1 mRNA expression was significantly higher than those of control group B and positively correlated with pelvic floor ultrasound parameter BND. Conclusion: The patients with stress urinary incontinence have the ultrasonic characteristics of weak pelvic support and enhanced urethral activity, and the abnormal collagen metabolism and excessive apoptosis are closely related to the changes of pelvic floor.