Abstract: The final microstructure distribution in high-strength steel large complex components is uniform throughout the multi-pass forging process, owing to the difference in deformation amount in different regions of large complex components. The uniformity can significantly affect the final service performance of the forgings. Therefore, a prediction analysis system for the microstructure evolution of high-strength steel large complex components during the multi-pass forging was developed based on DEFORM3D software. The reliability of the established prediction analysis system exceeds 0.98, as verified by the experimental data. The microstructure evolution rule of high-strength steel large complex components during the multi-pass forging under local temperature control was studied by utilizing the system. The results show that the local temperature control technology can effectively improve the uniform microstructure distribution of high-strength steel large complex components. The research provides a novel process method for high-performance forming of large complex components.