Abstract: Objective: To explore the mechanism of Fuyanqing Granule for treating pelvic inflammatory disease (PID).Methods: Sixty SD rats were randomly selected according to the random number table method, with 15 rats assigned to the normal group and the remaining 45 rats assigned to the model group.The PID rat model was established by mechanical scratching combined with lipopolysaccharide induction. After successful modeling, the normal group received no intervention, while the model group was randomly subdivided into 5 groups: model group (equal volume of normal saline), low-, medium-, and high-dose Fuyanqing Granule groups (2, 4, 8 g/kg·d, respectively), and Fuke Qianjin Capsule group (0.52 g/kg·d). All groups were treated with intragastric administration for 28 consecutive days. HE staining was used to observe the pathological changes of uterine tissues. ELISA was performed to detect the serum concentrations of IgG, IgA, IgM, sICAM-1, TNF-α, and IL-1β. RT-qPCR was used to determine the mRNA expressions of RORγT, IL-17, Foxp3, and IL-10 in uterine tissues. Immunohistochemistry (IHC) was employed to detect the positive expressions of Notch1, Notch2, Jagged1, Jagged2, Hes1, Hes5, and ICAM-1 in uterine tissues. Western blot was used to measure the protein expressions of Notch1, Notch2, Jagged1, Jagged2, Hes1, Hes5, RORγT, IL-17, Foxp3, and IL-10 in uterine tissues.Results: Fuyanqing Granule alleviated uterine congestion, edema, adhesion, and inflammatory infiltration in PID rats. It increased the serum concentrations of IgG, IgA, and IgM, decreased the levels of TNF-α, IL-1β, and sICAM-1, upregulated the expressions of Foxp3 and IL-10, and downregulated the expressions of RORγT, IL-17, and ICAM-1 in uterine tissues, thereby restoring the Th17/Treg immune balance. Additionally, Fuyanqing Granule inhibited the excessive activation of ligands (Jagged1, Jagged2), receptors (Notch1, Notch2), and target genes (Hes1, Hes5) in the Notch signaling pathway. Its therapeutic effect was comparable to that of Fuke Qianjin Capsule.Conclusion: Fuyanqing Granule may treat PID by inhibiting the Notch signaling pathway, regulating the Th17/Treg immune balance, enhancing immune function, and improving the inflammatory microenvironment.