Abstract: A stenosis assessment method and device based on the intracranial digital subtraction angiographic (DSA) imaging, including acquiring the intracranial DSA imaging and extracting two planar images containing the target blood vessel from the DSA imaging, wherein the two planar images have different shooting angles. According to the two planar images, a 3D model of the target vessel is established. Based on the established 3D model of the target vessel and the DSA imaging, the hemodynamic simulation of the target vessel is performed. The disclosure realizes the functional assessment of intracranial vascular stenosis, improves the diagnostic accuracy, and provides certain assistance for neurologists to determine intervention means. The disclosure of noninvasive FFR technology in the assessment of intracranial vascular stenosis can only rely on angiography for functional assessment, saving the medical examination cost of patients. It has more convenient operation and higher repeatability.