Abstract：Professor YANG Yanxian focuses on the fundamental pathogenesis of spleen and kidney deficiency in premature ovarian insufficiency （POI）. Guided by the theory of "mutual support between the spleen and kidney，" she applies Chinese medicine cyclical sequential therapy to manage POI through stage-specific treatment： during the follicular phase， the emphasis is on supplementing qi and nourishing blood， as well as mutual nourishment of the spleen and kidney， to replenish the thoroughfare and conception meridians；during the luteal phase，the focus is on tonifying the kidney，enriching essence，and consolidating the foundation and cultivating the vital essence to support conception and regulate menstruation. The treatment equally emphasizes the spleen and kidney， adapts to the natural rhythm， and implements cyclical regulation， fully leveraging the synergistic effect of "mutual support between the spleen and kidney" in balancing qi，blood，yin，and yang.