To investigate the correlation between three-dimensional ultrasonography parameters and pelvic floor dysfunction (PFD) and its application value in diagnosis and treatment. 92 patients with PFD and 22 without who underwent three-dimensional ultrasonography were selected. Transperineal three-dimensional ultrasonography was performed by Voluson E8 color Doppler ultrasonography to analyze the anteroposterior diameter (LHAD), transverse diameter (LHLD), pelvic diaphragmatic hiatus area (LHA), and bladder neck mobility (BND) of the patients. Diagnostic sensitivity and specificity of ultrasound parameters in PFD were analyzed using ROC curves. Paired sample t test was used to analyze the improvement of PFMT in patients with PFD. Patients with PFD had significantly higher levels of △LHAD, △LHLD, △LHA and BND than controls (all P < 0.01). Binary logistic regression analysis showed that △LHA or BND levels were independent risk factors for the development of PFD. The ROC results showed that the area under the ROC curve with BND level was the highest (0.917). The diagnostic sensitivity of BND in PFD was 100.0% and the specificity was 70.7%. In Urinary incontinence (UI) patients, there was a significant positive correlation between the occurrence of UI and BND levels (all r > 0, P < 0.05). After PFMT treatment, the levels of △LHAD, △LHLD, △LHA and BND in patients with PFD were significantly decreased (all P < 0.001). The abnormal changes in the level of three-dimensional ultrasound parameters can be used as a sensitive indicator to evaluate PFD and a guiding parameter for PFMT treatment. The feasibility of operation and repetition by three-dimensional pelvic floor ultrasonography could provide a reliable imaging basis for clinical diagnosis and treatment of patients with PFD.