Objective To evaluate the therapeutic effect of carotid artery stenting (CAS) on carotid artery stenosis with computational fluid dynamics. Methods Three-dimensional reconstruction of CT images before and after operation was conducted with Mimics software in one patient with carotid artery stenosis. Individualized carotid artery bifurcation model was constructed, and computational fluid dynamics was employed to perform three-dimensional fluid numerical simulation calculation. The therapeutic effect of CAS was evaluated with hemodynamic parameters of wall shear stress, wall pressure, blood flow tract and blood volume. Results Numerical simulation calculation indicated that compared with those before operation, there were significant changes in carotid blood flow velocity, blood flow distribution between internal carotid artery and external carotid artery, wall shear stress and wall pressure, and the blood flow state was significantly improved. Conclusion Computational fluid dynamics numerical simulation is rational in evaluation of therapeutic effect of CAS, and can provide individualized optimal guidance before operation.