Abstract: Analyzed in the paper are the development and limitation of the process and the equipment of "bath quenching" and "external spraying quenching". Also elaborated are the innovative process of "external spraying + internal spraying + semi-immersion + rotation",as well as the multi-functional equipment and the advantages. Compared with the operation cases of the "bath quenching" process and "external spraying quenching" process,the modification scheme of the "external spraying+internal spraying+semi-immersion+rotation" process and the actual application result are described in details. Thanks to the modified quenching line,the product mix is expanded,the product quality and the production efficiency are enhanced,and both the production resource consumption and manpower cost are reduced.