With the high pressure rotor system of an aero engine as the object of study, in the context of uneven radial distribution of steady state temperature field, this paper establishes FEM model of 3D solid elements of a high pressure rotor system and vibration equation of thermal structural coupling model of 3D solid rotor system in the steady state temperature field, it first makes an analysis of the steady state temperature field by indirect coupling method using thermal structural dynamic coupling theory, and then makes a static analysis to generate thermal stress, and then generates global stiffness matrix by setting prestress option to make a modal analysis, and finally makes an analysis of coupling response of unbalance and thermal bending by modal superposition method to realize thermal structural dynamic coupling computation. Through the analysis of the effect of steady state temperature field on steady state response of typical stage discs and analysis of steady state response of coupling of unbalance and thermal bending, this paper finds coupling response has a big effect on vibration response of different stage discs of the rotor system.