Objective To investigate the application of accurate endoscopic retrograde cholangiopancreatography （ERCP）drainage guided by IQQA-Liver CT(an image interpretation and analysis system)to preoperative jaundice reduction for hilar cholangiocarcinoma. Methods Data of 12 patients with hilar cholangiocarcinoma who planned to receive surgical treatment in the hepatobiliary surgery department of Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School from May 2017 to December 2018 were reviewed. All patients were treated with ERCP drainage before surgery. The procedure success rate, postoperative drainage volume and postoperative complications of the patients were analyzed. Results ERCP was successful in all patients, and the median daily volume of endoscopic nasobiliary drainage was 675 mL(400-1 500 mL). Only 1 patient developed postoperative cholangitis, and another patient developed postoperative mild pancreatitis. The mean serum total bilirubin was 173.3±62.8 μmol/L in the patients before ERCP, which decreased to 35.6±13.9 μmol/L before surgery. Conclusion Accurate ERCP drainage can effectively reduce the serum bilirubin level in patients with hilar cholangiocarcinoma and reduce the incidence of cholangitis after the procedure, creating favorable conditions for subsequent surgical operations.