Astragalus membranaceus, with a slightly warm nature and a sweet taste, enters the spleen and lung meridians and is hailed as "the chief tonifying qi". Its core efficacy lies in greatly tonifying the qi of the spleen and lungs, which can significantly improve fatigue, poor appetite, loose stools and shortness of breath and lack of speech caused by qi deficiency. It can also consolidate the exterior and stop sweating. For the symptoms of spontaneous sweating and susceptibility to colds caused by exterior deficiency and instability, it is like adding a wind barrier to the human body. It can also promote diuresis and reduce swelling, treating edema caused by qi deficiency and water retention. It can also promote the growth of toxins into the skin and facilitate the healing of sores and ulcers. It can be regarded as a key medicine for tonifying qi and raising Yang, and a holy grail for treating deficiency syndromes and sores.