Accuracy is an important index of vascular interventional surgical robot system, and is influenced by the accuracies of image navigation and interventional robot, and random errors. Based on the vascular interventional surgical robot propulsive mechanism, a series of accuracy experiments are carried out, and the test results are analyzed, which validate that the propulsive mechanism satisfies the required design accuracy, and then the accuracy and error sources of propulsive mechanism are analyzed. Some methods to enhanced the propulsive mechanism accuracy are proposed for the mechanism design and improvement.