Spondylolisthesis is a congenital dysplasia, often associated with a variety of malformations such as hydrocephalus, and may have a local congenital tumor, but the coexistence of the three is extremely rare, the authors admitted a case with significant results, is reported as follows: clinical data male, 14 years old, due to progressive enlargement of the sacrococcygeal area for 3 years, disappears when standing, appears when sitting, about the size of a fist, in the local hospital without a clear diagnosis, and then CT examination was diagnosed as a pelvic cyst, and two months after surgery, recurrence. In early 2007, he gradually developed unsteadiness in walking, intermittent dizziness and weakness of both lower limbs, and was diagnosed as pre-sacral dural dilatation by MRI of the lumbosacral region. After admission, the fistula was repaired through a posterior sacral transverse arc incision, and the wall of the bulging cyst could be palpated under the deep fascia during surgery, with a sense of fluctuation and high tension when touched. The cystic neck was formed by gradually thinning behind the caudal bone and communicating with the spinal cord cavity. The white soap-like attachment on the wall of the tumor was removed, the tissues around the neck of the tumor cavity were fully freed behind the caudal bone, cut at the neck, the medullary cavity was flushed, and the stump was purse-sutured to close the spinal cord cavity and confirm that there was no cerebrospinal fluid outflow. Iodine was applied to the tumor cavity to disrupt its mucosa, and a drainage tube was built into the cavity and perforated for drainage. At the same time, external drainage by ventricular puncture was performed. The incision healed well one week after the operation. The lateral ventriculo-abdominal shunt was given and the patient recovered well on postoperative review of head CT. The fistula was repaired through the original incision and the patient was asked to rest in bed for two months after surgery. The patient was discharged from the hospital two weeks after the reoperative treatment and was placed on bed rest for two months. On review at three months, he was able to walk freely, control his bowels and urine spontaneously, and his dizziness and lower extremity weakness disappeared. The head CT was repeated and showed that the ventricle was shrunken. The pelvic CT showed that the cyst was significantly reduced.