Objective. To study the value of pelvic floor ultrasonography in evaluating pelvic floor dysfunction (PFD) after total hysterectomy for cervical cancer. Methods. All the enrolled patients were given 4D pelvic floor ultrasound examination before and after surgery. The results of ultrasonic examination and the parameters of four-dimensional ultrasonic examination before and after surgery were analyzed, and the quality of life of the patients before and after surgery was evaluated. Results. Postoperatively, the posterior angle of bladder and urethra, the rotation angle of urethra, the decreased value of bladder neck, and the distance between bladder neck and pubic symphysis were ( 122.60 ± 9.53 )°, ( 136.47 ± 14.67 )°, ( 58.90 ± 18.19 )°, ( 18.14 ± 7.32 ) mm, and ( 2.76 ± 0.46 ) cm, significantly greater than the preoperative ( 89.90 ± 9.59 )°, ( 107.30 ± 9.96 )°, ( 27.59 ± 10.96 )°, ( 13.27 ± 5.69 ) mm, and ( 2.24 ± 0.21 ) cm ( P < 0.05 ). Postoperative detrusor muscle thickness, bladder neck movement, residual urine volume, and bladder rotation angle ( 4.48 ± 0.82 ) mm, ( 0.64 ± 0.17 ) cm, ( 12.82 ± 2.69 ) ml, ( 12.11 ± 2.43 )° were significantly higher than those of preoperative ( 3.70 ± 0.64 ) mm, ( 0.43 ± 0.18 ) cm, ( 4.83 ± 1.07 ) ml, ( 4.30 − 1.19 )° ( P < 0.05 ). The scores of emotional function, psychological function, social function, and physiological function were ( 2.35 ± 0.75 ) points, ( 2.45 ± 0.66 ) points, ( 2.30 ± 0.77 ) points, and ( 2.19 ± 0.71 ) points, significantly higher than those of ( 1.01 ± 0.50 ) points, ( 1.25 ± 0.54 ) points, and ( 1.00 ± 0.57 ) points before surgery, ( 1.05 ± 0.46 ) ( P < 0.05 ). Conclusions. The application of pelvic floor ultrasonography to detect pelvic floor dysfunction after total hysterectomy can clearly display the anatomical structure of the pelvic floor, which is conducive to disease prevention and treatment. Four-dimensional pelvic floor ultrasound can clearly show the postoperative pelvic floor function, which is worthy of clinical promotion and reference.