Objective To study the effect of morphological characteristics of modular inner branched stent graft (MIBSG) on hemodynamic performance of postoperative aortic arch based on parameterized MIBSG model. Methods The fluid-structure interaction model of blood-MIBSG coupling performance was solved, and the effects of stent branch angles, stent diameters on hemodynamic characteristics were analyzed. Results With the increase of angles between branch stent and aortic arch stent, blood flow within the branch decreased, but the stress and displacement increased. With the decrease of stent diameters, blood flow perfusion decreased significantly, but the stress and displacement increased first, and then decreased. Conclusions The morphological changes of MIBSG not only have an impact on blood perfusion rate of branch stent, but also affect the stress exerted on stent and the corresponding displacement. Before application in clinic treatment of aortic arch diseases, the movement and torsion of MIBSG should been taken into full account in operation plan according to the actual situation.