The influence of temperature, strain rate, strain on mechanical parameters and microstructure evolution in isothermal deformation of GH4169 alloy were investigated. Lower resistance is obtained under higher temperature and or lower strain rate. However, coarser microstructure also is gained under such condition. The tensile property at room temperature and elevated temperature, permanent properties at elevated temperature of the GH4169 alloy with the treatment of “direct aging after isothermal deformation” are better than those of the same alloy with the treatment of solid-solution+direct aging after isothermal deformation. Isothermal forming was undertaken for a 1/4 size simulated part of a kind of turbo disk of an aviation engine. Its external is fine and the microstructure of the material was fine and homogeneous for both straightly after forming and after direct aging.