Objective To investigate effects of endovascular stents with different structures and wire cross section shapes on the treatment of internal carotid aneurysm and its influence on hemodynamics and flexibility. Method Based on the same model of internal carotid aneurysm, five models with different stent intervention treatment were constructed, which had different stent structions or wire cross section shapes while their porosity rates were approximately the same. Numerical simulations were performed using finite volume method to get quantitative information of biomechanics. Results Among the five models, the mean flow rate in aneurismal cavity decreased maximally in the model with stent of rectangular cross section. Wall shear stress in aneurismal dome and aneurismal neck were found to decrease much more in models with circular cross section and rectangular spiral stent. The flexibility of mesh stent was far better than that of the spiral stent. Conclusions Mesh stent with rectangular cross section has better biomechanical influence on the treatment of internal carotid aneurysm. These findings may help clinicians to select a proper stent when treating arterial aneurysm.