The prescriptions of professor zhang yuzhen for the treatment of pcos patients in late menstrual period from March 2017 to June 2019 were collected, and the TCM Inheritance Support Platform(V2.5) was used to analyze the syndrome distribution and medication rules. Results a total of 636 prescriptions were included, involving 157 herbs, including 6 syndromes, which were successively kidney deficiency and liver stagnation, spleen deficiency and phlegm-dampness, liver meridian stagnation and fire, spleen and kidney deficiency, qi stagnation and blood stasis, and liver stagnation and spleen deficiency. The association rules were used to analyze the prescription of each syndrome type, and the key prescription was obtained. The analysis results suggested that Professor Zhang Yuzhen’s treatment of PCOS in the late menstrual period was mainly to invigorate the kidney, strengthen the spleen and dredge the liver, and at the same time taking into melt dampness, clearing heat and activating blood circulation. It embodies the treatment idea of“treating from liver, spleen and kidney, Combining supplement with attack, harmonizing qi, blood and water”.