The 3-year-old patient went to the doctor for "palpating the right upper abdominal mass". Ultrasound and CT examination showed right hepatoblastoma with tumor thrombus in portal vein and splenic vein. As there is no indication for surgery, multidisciplinary consultation suggests ultrasound guided puncture biopsy. Therefore, ultrasound guided liver mass biopsy was performed under general anesthesia. Postoperative pathological diagnosis was hepatoblastoma. On the 4th day after operation, the child suffered from acute abdominal pain, and did not clot after abdominal perforation. He recovered well after intravascular embolization and blood transfusion. It is suggested to strictly control the surgical indications for young children before operation, extend the pressure of puncture points during operation, inject hemostatic drugs through coaxial needles and extend the braking time after operation to reduce the risk of severe bleeding.