The high-concentration pickling and the extreme emission and energy consumption of the precision saponification process before the cold finishing of the precision forgings of the constant speed drive shaft of the car. Oil mist emissions from the cold finishing process and relatively harsh working conditions. The purpose of this paper is to develop a new saponification process that saves energy and reduces emissions while ensuring product quality during production. Through a large number of tests, it shows that the saponification of precision forgings for the drive shaft can be completed by three steps including simple saponification liquid spraying, liquid extraction and hot air drying. Thus in this way, the saponification quality is the best, At the same time, it has greatly reduced emissions, while the instability of the saponification quality mainly relates to the control of saponification process.