Abstract: A precise forming process of GH188 alloy profiled casing ring forging with large taper, thick flange, high height was introduced. Using the profiled rolling sub-material +the loose mold forming +the precise rolling technology,combined with the numerical simulation technology, the detailed process parameters were determined, the large complex section GH188 alloy profiled casing forging with uniform structure were successfully prepared. The results show that the prepared profiled casing forgings have a high material utilization rate, good cross-section filling effect, the section grain size of the forging is 3.5 grade, the microstructure is uniform, and the performance meets the technical requirements.