To meet the design requirements of higher thrust-to-weight ratios for the new generation of aeroengines,laminate structures have gradually become a research hotspot. GH4099 and GH3128, as typical nickel-based superalloys,are widely used in laminate structures because of their excellent high-temperature strength, oxidation resistance and creepresistance. However, direct diffusion bonding is prone to produce pores and carbide defects, resulting in low joint strength.Therefore, this study aims to systematically investigate the influence of diffusion bonding temperature (1 040~1 160 ℃) onthe microstructure and mechanical properties of GH4099/GH3128 joints by adding a 3 μm Ni foil interlayer to optimize theprocess parameters and improve the mechanical properties of the joints. The microstructure and mechanical properties werecharacterized by scanning electron microscopy (SEM) and tensile tests. The results show that the Ni interlayer caneffectively eliminate interface pores, and the solid solution effect of Ni on C causes a carbon-poor zone to form at the jointinterface; carbides containing W and Mo precipitate on the GH3128 side, and a small amount of the γ′ phase is generatedon the GH4099 side; when the bonding parameters are 1 120 ℃-10 MPa-60 min, the mechanical properties of the joint areoptimal, with a tensile strength of 938 MPa and an elongation of 17%.