Abstract: The effects of solution temperatures, rolling temperatures and deformation amounts on the abnormal grain growth（AGG） in GH4738 superalloy were investigated through solution heat treatment and wedge-shaped sample rolling experiments. The results indicate that the average grain size of the alloy gradually increases with the rise of solution temperature. Wedge-shaped samples subjected to sub-solid solution heat treatment at 1030 ℃ and hot rolling at various rolling temperatures and deformation amounts, exhibit relatively fine and uniform microstructures, with no abnormal grain growth observed. However, wedge-shaped samples treated with sup-solid solution heat treatments at 1080 ℃ and 1120 ℃ and hot rolling under varying conditions, show abnormal grain growth at deformation amounts of 10% and 20%. The critical temperature for abnormal grain growth in the alloy is determined to be 1060 ℃, with a critical deformation amount between 10% and 20%. Selecting a deformation amount of 20% or higher can effectively prevent abnormal grain growth, resulting in a uniform grain structure. When the solution temperature is constant, the hardness of the alloy gradually increases with the increase of rolling deformation. However, when the rolling temperature is constant, the hardness of the alloy gradually decreases with the increase of solution temperature. The research results provide important guidance for controlling abnormal grain growth in GH4738 superalloy.