Pelvic floor dysfunction disease has a high incidence in women after pregnancy. During this special physiological period of women pregnancy, posture of woman pelvis will change, and the pelvic biomechanics will change as well. Such mechanical changes will bring corresponding diseases. The relationship between dynamic changes and occurrence of functional disorders were discussed, the influences of changes in abdominal pelvic mechanics on the pelvic floor after pregnancy were summarized, and the high risk factors of pelvic floor dysfunction （PFD） were investigated, so as to provide the optimal treatment plans and method for pelvic floor rehabilitation treatment.