Non-lactation mastitis is a group of chronic non-bacterial inflammatory diseases occurring in the breast, with breast lumps, abscess, sinus tract and fistula as its main manifestations. It relapses and is difficult to heal. According to the three different stages of the disease, namely the initial stage, the purulent stage and the ulceration stage, the internal treatment method of TCM surgery establishes three treatment principles of elimination, supporting and tonification, among which the supporting method is the most representative characteristic therapy. Half-yin and half-yang syndrome is the most common type. In terms of treatment, clearing and elimination are mainly used for yang syndrome and warming method is mainly used for yin syndrome, and supporting method is more appropriate for half-yin and half-yang syndrome. The specific application of the supporting method in non-lactation mastitis is discussed in this article from the perspective of clearing-supporting method to outthrust the pathogens, supporting the interior to bring out the pus and to generate fleshes, in combination with other methods. According to the theory of the supporting method for non-lactation mastitis and based on disease differentiation and syndrome differentiation, the "No.2 formula" , used for the purulent stage and the ulceration stage, is introduced in terms of its specific drug use in combination with clinical cases.