Objective:To analyze the hemodynamic changes of different types of unruptured intracranial aneurysms before and after flow diverter (FD) treatment with computational fluid dynamics (CFD), and lay research foundation for precision treatment and prognosis evaluation for unruptured intracranial aneurysms.Methods:Four patients with different types of unruptured intracranial aneurysms, admitted to Department of Neurosurgery, First Affiliated Hospital of Air Force Medical University from January 2022 to March 2022, were chosen. Digital subtraction angiography (DSA) data of the patients before and immediately after surgery were collected. Morphological and hemodynamic parameters of the aneurysms were calculated by 3D reconstruction, finite element simulation, and CFD methods: ostium ratio (OsR), neck ratio (NR), area ratio (ArR), volume ratio (VoR), wall shear stress (WSS), normalized wall shell stress (NWSS), blood inflow, relative inflow, aneurysm average velocity, parent artery average velocity, normalized velocity, residual flow volume (RFV), and inflow concentration index (ICI); differences of these indexes before and after treatment were compared.Results:The OsR of 6 aneurysms was 0.225, 0.267, 0.265, 0.389, 1.000, 1.000, respectively; NR was 1.220, 0.274, 1.090, 1.587, 2.809, and 4.019, respectively; ArR was 0.608 and 0.224, 0.623, 3.462, 1.225 and 1.784, respectively; and VoR was 0.386, 0.052, 0.212, 3.462, 0.422 and 1.882, respectively. The parameters of WSS, NWSS, blood inflow, relative inflow, aneurysm average velocity, parent artery average velocity, normalized velocity, RFV, and ICI decreased obviously after FD implantation.Conclusion:On the basis of 3D reconstruction combined with FD/coil virtual implantation, CFD-based hemodynamic analysis can obtain accurate parameters of different types of intracranial aneurysms before and after FD treatment.