Background. Using network pharmacology and molecular docking, this study aimed to explore the active pharmaceutical ingredients (APIs) and molecular mechanism of Qinshi Simiao San (QSSMS) in the treatment of chronic prostatitis (CP) and verify our findings in the rat model. Methods. The APIs of QSSMS and the common targets of QSSMS and CP were screened from the TCMSP database. The STRING database and Cytoscape software were used to construct the network graph. The enriched GO and KEGG pathways were displayed by David software and R software. Molecular docking was performed to visualize key components and target genes. In addition, the rats model of CP was established to verify the molecular mechanism of QSSMS. Results. Network pharmacology showed that the APIs of QSSMS mainly included quercetin, kaempferol, formononetin, isorhamnetin, and calycosin. QSSMS alleviated CP mainly through the negative regulation of the apoptotic process, oxidation-reduction process, inflammatory response, and immune response. Molecular docking showed that the APIs could bind to the corresponding targets. QSSMS repaired the pathological damage of prostate tissue, upregulated the expression of oxidative stress scavenging enzymes CAT and SOD, and downregulated the peroxidative product MDA, inflammatory factors IL-1 beta, IL-6, TNF-alpha, COX-2, PGE2, and NGF, and immune factors IgG and SIgA. Conclusion. The APIs in QSSMS may inhibit inflammation in the rat CP model by regulating immune and oxidative stress.