Abstract: The material of the large annular thin-walled forging is 30CrMnSiA, the maximum diameter is Φ1630mm, the height is 230mm, the wall thickness is about 25mm, the hardness after quenching and tempering is required to meet HRC33-38, and the deformation shall not exceed 3.28mm. Through the study of its main technical requirements, a special heat treatment process is prepared for the forging: the quenching temperature is set at 900 °C, the quenching and heat preservation time is 1~1.5 hours, the average temperature is also required for 1 hour in the heating process, the average temperature is set at 650 °C, and the cooling adopts oil cooling; The tempering is set to a temperature range of 480~550, the tempering and holding time is 4~6 hours, and the cooling is water-cooled. In order to solve the problem of inconvenient lifting and deformation of forging after heat treatment, a special tooling is designed, and the material used in the tooling is mainly Q235-A, which is processed by welding, and the processing cost of tooling is reduced. After heat treatment by using special technology and tooling, the hardness value and deformation of multiple forgings are detected, and the hardness value is HRC35-38, and the deformation is controlled within the range of 3.28mm. It effectively solves the problem of insufficient hardness and excessive deformation in the process of quenching and tempering of the forging, and provides an effective solution for the company's production and manufacturing of this type of workpiece.