Breast cysts during lactation are mostly due to poor discharge of milk from one lobe of the gland, which accumulates in the breast and forms cysts, also known as cumulative breast cysts or milk retention cysts. After the diagnosis is clear, the following treatments can be performed: first, puncture and aspiration, when performing needle aspiration cytology examination of the swelling, if milk-like fluid is aspirated, the cystic tissue should be aspirated at once, and when the milk is aspirated and the cyst shrinks, the residual cystic cavity is bandaged with pressure, which can be cured in a few cases. Secondly, simple removal of cyst, if the cyst is repeatedly inflamed and infected or continuously enlarged, simple removal of cyst can be performed under local anesthesia. If it is accompanied by acute inflammation, anti-inflammatory treatment should be performed first, and then surgery should be performed after breastfeeding. Thirdly, the treatment of Chinese herbal medicine, the type of liver stagnation and qi stagnation is based on draining liver and dispersing qi, and the type of qi stagnation and blood stasis is based on regulating qi and activating blood stasis. For these two methods, different medical prescriptions are used according to different types of treatment.