Abstract: Using powder metallurgy superalloy FGH4096 as research object, on the basis of isothermal deformation,using the microstructure module of Deform software, combined with the Avrami model and cellular machine（CA） method,the heat treatment process of FGH4096 superalloy was simulated. The evolution of deformation microstructure during heat treatment and the influence of heat treatment parameters（heat treatment temperature, heat treatment time） on deformation microstructure were studied. The results show that the recrystallized grains in the microstructure where the deformed samples are heat treated and the recrystallized grains coexist with the deformed original grains grow gradually, and eventually replace the original deformed grains. Increasing heat treatment temperature greatly increases grain growth rate. When the holding time is prolonged, the grain size changes little at lower temperature, and the grain grows rapidly at higher temperature.