The case of penetrating injury of the kidney caused by a foreign body mistakenly swallowing through the duodenum is rare. A 22-year-old male patient found that a strip of the foreign body penetrated the descending duodenum - the lower pole of the right kidney through an abdominal CT examination. After Multi-Disciplinary treatment, the patient underwent extracorporeal ultrasound-assisted endoscopic foreign body removal and hemostatic clamp suture. Extracorporeal ultrasound monitoring and intravenous pyelography showed that there was no leakage of contrast medium around the right kidney. No hematuria and urinary tract infection were found during the follow-up.