Postmenopausal osteoporosis (PMOP) is an important part of primary osteoporosis, and the current clinical treatment program for PMOP is easily limited by side effects and adverse reactions, so it is particularly important to seek more efficient, safe, and economical drug treatment for PMOP. In recent years, with the change of disease treatment mode and the gradual deepening of Traditional Chinese medicine (TCM) research on PMOP, a review of the literature reveals that there is a huge number of studies on the use of TCM in the treatment of PMOP, but there are no relevant systematic studies on the rules of its formulas and the specific mechanisms by which the core drugs exert their therapeutic effects. Therefore, in this study, we collected a total of 141 formulas used by TCM clinicians to treat PMOP, statistically analyzed their high-frequency medications, Four Qi, Five Flavors, meridians, and efficacies, and analyzed the core medications based on the association rules, which were Rehmanniae Radix Praeparata, Epimedium, Eucommia ulmoides, Rhizoma Drynariae, Angelica sinensis, Achyranthes, Astragalus propinquus, Psoralen, Cornus officinalis and licorice. A total of 87 drug pairs were obtained from the correlation analysis, and a total of 8 groups of potential core combination drugs and 4 potential new prescriptions were derived based on the cluster analysis. Subsequently, a network pharmacological analysis of the core drugs was conducted to obtain 173 active ingredients in the core drugs, including kaempferol, β-sitosterol, quercetin, etc. 298 targets of action, including MAPK3, STAT1, HSP90AA1, etc. 170 signaling pathways including AGE-RAGE, PI3 K/Akt, TNF, HIF-1 and others. The molecular docking results showed that 11 key active ingredients in the core drugs had stable binding to the target targets. This study showed that TCM treatment of PMOP is mainly based on “reinforcing liver and kidney, warmly invigorating spleen and stomach, activating blood and resolving stasis.” Core drugs therapy for PMOP is a comprehensive intervention through multi-component, multi-target, and multi-pathway approaches. The minimum binding energies between the 11 key active ingredients and the 11 key targets were calculated in a comprehensive analysis, which shows that the core drugs have good binding activities to their therapeutic targets, proving that the predictions of this study are reliable. In the future, it will provide certain medication basis and data support for TCM treatment of PMOP.