The utility model discloses a method by use of digital sequence subtraction angiographic images to segment vascular data, which makes use of standard deviation of statistics to describe the changing information of pixel gray value of each point on images along with time. By calculating the gray value standard deviation of each pixel point, 0 to 255 gray space is mapped and a feature graph describing the change of each pixel is obtained. The standard deviation of the area with bigger change of pixel gray value in time, namely, the objective vascular area, is a little bigger. The object is strengthened if reflected in the feature graph. The standard deviation of the area with smaller change of pixel gray value in time, that is the area with no blood vessel, is a little smaller. The background is weakened if reflected in the feature graph; the utility model adopts partial threshold value segmentation method on a basis of busyness measurement, carries out the binary segmentation on the feature graph, then makes use of marking technology of maximum communication domain and the connectivity of vascular tree in structure and wholly segments the vascular tree.