Abstract: Under the welding parameters that spindle speed was 650 r/min, moment of inertia was 340 kg·m² and welding pressure was 450 MPa, GH4169 and FGH96 was welded by inertial friction welding. Under the action of welding pressure and welding heat cycle, the microstructure of different parts of the welded joint changed, the grains appeared to be refined and deformed to different extents, and the matrix strengthening phase dissolved and deformed to different degrees of dissolution and deformation. Affected by the heat-force coupling effect of the welding, the microhardness of the welded joint was characterized by a "mountain peak" distribution. Mechanical properties of welded joints were tested and analyzed:the average tensile strength of welded joints was 1 366 MPa, and the average tensile strength of high temperature was 1 176.7 MPa. The average long-lasting life was 215 hours at 650℃ and 641 MPa. The welded joint had good comprehensive mechanical properties.