Abstract： Objective： To study the Chinese medicinal medication rules of treating polycystic ovary syndrome (PCOS) in the real world based on the data mining of Hospital Information System (HIS). Methods： The cases of 208 patients who received effective treatment in the Gynecology Department of Yuyao Maternity and Child Health Care Hospital and Hubei Provincial Hospital of Traditional Chinese Medicine from November 2020 to April 2022 were selected， and their medical records were entered into the Integrated Electronic Medical Record System for Clinical Research. An Excel database was established， and Python Language Package was used for calculation； Apriori algorithm was used to analyze the strength of association between prescribed medicines. And based on the entropy hierarchical clustering algorithm， the analysis of new prescriptions was carried out and the administration rules of treating PCOS in the real world was summed up and analyzed. Results： A total of 208 patients were included，involving 713 prescriptions and 157 Chinese medicinals，with a total frequency of 8 163 times. The high-frequency Chinese medicinals included Semen Cuscutae (352 times)， Pseudostellariae Radix (343 times)，Dipsaci Radix (319 times)，Atractylodis Macrocephalae Rhizoma (276 times) and Cistanches Herba (264 times). The medicinal natures were mainly warm，followed by cold and neutral. The medicinal flavors were mainly sweet or bland，followed by acrid and bitter or astringent. The channel entries were mainly the liver channel，the kidney channel and the spleen channel. The therapeutic effects of the herbs were mainly deficiency-supplementing herbs， followed by blood-invigorating and stasis-dissolving herbs， qi-rectifying herbs and heat-clearing and toxins-resolving herbs. Based on association rule analysis， 12 pairs of herbal pairs and 15 groups of triplet medicinals were obtained， among which the commonly used herbal pairs were Pseudostellariae Radix-Cistanches Herba，Pseudostellariae Radix-Cervi Cornu Degelatinatum， Pseudostellariae Radix-Atractylodis Macrocephalae Rhizoma， Pseudostellariae Radix-Dendrobii Caulis， and Pseudostellariae Radix-Taxilli Herba， and the commonly used triplet medicinals were Pseudostellariae Radix-Dendrobii Caulis-Dipsaci Radix， Pseudostellariae Radix-Dipsaci Radix-Cuscutae Semen，Pseudostellariae Radix-Atractylodis Macrocephalae Rhizoma-Dipsaci Radix，and Pseudostellariae Radix-Dipsaci Radix-Cistanches Herba. Based on cluster analysis， five groups of new prescriptions were obtained， which mainly included herbs for tonifying the kidney， supplemented with herbs for soothing the liver，strengthening the spleen，dispelling stasis and resolving phlegm. Conclusion： The core pathogenesis of PCOS is kidney deficiency and liver constraint. The mainly used herbs are sweet and warm，and enter the liver channel. The commonly used herbal pairs，triplet medicinals and core herbal combinations all reflect the treatment methods of tonifying the kidney， soothing the liver， invigorating blood，resolving phlegm and so on.