Abstract: The quality of heat treatment of mandrel directly determines the service performance and service life of functional components of electric spindle products.In view of the quality problem of excessive deformation of the core shaft quenching volume,the controlled atmosphere multi-purpose furnace is used to quench the electric spindle,which not only solves the problem of environmental protection that has plagued enterprises for a long time in salt bath heat treatment,but also unlocks the new function of the controlled atmosphere multi-purpose furnace to ensure product quality.The successful test of this process is of great significance to the improvement of heat treatment quality of key functional parts of mandrel.