Provided is a system for supporting the treatment of vascular diseases by performing a blood flow simulation based on a medical image, the system comprising: an input unit that reads the medical image, fluid properties and boundary conditions from a data storage unit； a blood flow analysis execution unit that obtains a pressure field and a flow velocity field based on the medical image read by the input unit； a blood flow information calculation unit that calculates, based on the pressure field and the flow velocity field, blood flow information about a specific blood vessel being treated； a vascular treatment risk assessment unit that calculates, based on the calculated blood flow information, the proportion of a blood flow volume flowing into an aneurysm as a risk factor associated with the vascular treatment of the blood vessel being treated； and display units that display the calculation results to a user.
