To study the effects of stiffness characteristics on the working behavior of bolted joint with curvic coupling of heavy duty gas turbine, a stiffness analytical model was established with parametric modeling method. The curvic contact pressure, rotation stiffness, compression deformation have been derived by the proposed method, the deformation and stiffness change of all parts of the curvic coupling are investigated during the bolt tightening by finite element analysis and experimental method. The validity of the method is proved by experiments and finite element simulation. The results show that the bending behavior on the curvic and the cylinder part of the disc in bolt tightening, the curvic compression stiffness increases sharply and the stiffness data of other parts decreases slightly during bolt tightening process. The change laws including deformation, stiffness, contact stress, contact status of contact surfaces in curvic coupling are different from those in usual couplings.