Objective To explore the mechanism of Bushen Qiangdu Zhilou Decoction (补肾强督治偻方) in treating ankylosing spondylitis (AS) by network pharmacology methods.Methods The target genes of Bushen Qiangdu Zhilou Decoction were obtained in pharmacology component analysis platform of Chinese medicine system (BAT-MAN).The Target genes corresponding to AS were obtained in the Comparative Toxicogenomics Database (CTD).The target genes of the disease-drug protein were obtained after the intersection of the fore-mentioned two target genes.The interprotein interaction network was constructed by network visualization software STRING and the results were showed by network visualization.The important key genes were screened by calculation and analysis algorithm of network structure and inter node weighting connection.Gene ontology (GO) analysis of disease-drug intersection target genes and KEGG pathway enrichment analysis were made by DAVID on line tools.At last,the therapeutic effect of key genes in AS was obtained in CTD.Results There were 705 intersection genes of Bushen Qiangdu Zhilou Decoction target genes and AS disease target genes.GO analysis results showed that the biological function of intersection target genes of Bushen Qiangdu Zhilou Decoction and AS mainly included positive regulation of gene expression and inflammatory reaction,as well as positive regulation of cell proliferation.The signal pathway enrichment results showed that the network of intersection target genes of Bushen Qiangdu Zhilou Decoction and AS mainly involved Tumor necrosis factor signal pathway,estrogen signal pathway and T cell receptor signal pathway.Twenty-three key genes were obtained,which related to pain,inflammatory diseases,and arthritis.Conclusion Bushen Qiangdu Zhilou Decoction treating AS is a multi target,multi path,and multi choice process with complex mechanism.The mechanism might be related to anti-inflammatory and analgesic.