The recrystallization process of hot deformed austenite of TRIP steel was predicted using Cellular Automaton (CA) combined with the principles of physical metallurgy. A model was developed for prediction of the dynamic and static recrystallization microstructure evolution and properties of hot deformed austenite for TRIP steel. The theoretical modeling of recrystallization was based on dislocation density. The microstructure evolution of austenite recrystallization of TRIP steel (such as the grain shape and size, volume fraction, kinetics curve of recrystallization) was predicted both visually and quantitatively. The distribution and variation of the dislocation density and flow stress were also obtained, and the effects of silicon content on recrystallization for TRIP steel were analyzed. The CA calculation results were in good agreement with the measured ones.