Manufacturing dual superalloy turbine rotor is becoming an important direction of development in the field of aviation and aerospace. In order to improve working temperature and service life of turbine rotor, blade materials have been evolved to single crystal superalloys, turbine disc materials have also been developed to powder superalloys. Therefore the connection of these two materials has become key problem in improving turbine performance. Nowadays hot isostatic pressure (HIP) bonding is a preferable bonding technique due to no fusion and macroscopic deformation in bonding area. In HIP bonding process, elements diffusion is the key factor in forming microstructure of interface, and determining interfacial properties. At present, articles about HIP diffusion bonding mainly focused on interfacial microstructure and mechanical test of bonding couples, while few articles explored the relationship between elements diffusion and microstructure forming. In this work, diffusion couples of DD407 and FGH95 alloys were conducted under 1120, 1170, 1210℃ and 120 MPa HIP for 3 h, the microstructure and elements distribution of interface were studied to verify simulated results in the last article, and explore interface formation mechanism. Then the relationship between simulated phase distribution and actual microstructure of interface was built, which can be used to forecast interface morphology. And also the recrystallization in bonding zone was studied. Combining simulated and experimental results, this work put forwards principles for HIP bonding process controlling.