Abstract: Objective To explore the value of 3-dimensional digital subtraction in the diagnosis and treatment of the obstructive jaundice caused by the malignant tumours.Methods Twenty patients with obstructive jaundice caused by the advanced stage of malignant tumours were examined with 3-dimensional digital subtraction after the the Ultrasonic Guide Puncture intrahepatic bile duct extension,injecting the contrast material.Then the 3-dimensional imaging on the inspection results were conducted and pathological changes were observed.At the same time,draw another twenty medical case of this kind of terminal disease without 3-dimensional digital subtraction images in the corresponding hospitalized treatment period randomly.Next,conduct the comparison and analysis of the observation data with the two groups of patients.Results 3-dimensional digital subtraction images demonstrated the position,precision length of the bile duct malignant stricture,the shape of the stricture part of the pathological changes clearly,which contributes to the precise localization and the selection of suitable treatment method.And through the comparison,we found that the contrast material and total radiation dosage had been reduced and the operation process had been shortened distinctly in the cases with 3-dimensional digital subtraction images.Conclusion The 3-dimensional digital subtraction can reduce the operation time,decrease the dosage of contrast material and radiation.It plays an irreplaceable role in the diagnosis of the obstructive jaundice caused by the malignant tumours,in the precise measurement of the pathological changes,in the selection of the suitable therapy.