Wuzi Yanzong decoction (WZYZD) belongs to the traditional formula for treating male infertility caused by oligoasthenozoospermia (OLI). This research aims to elucidate the therapeutic substance basis and potential pharmacological mechanisms of WZYZD in treating OLI. A total of 52 chemical ingredients were identified from WZYZD. HE and TUNEL staining demonstrated that WZYZD can markedly alleviate OLI. Immunofluorescence analysis showed that WZYZD can significantly increase the expression levels of DNMT3 A, PIWIL1, SETDB1, and PRMT5. Methyl capture sequencing proved that WZYZD can markedly upregulate the methylated level of Spata, Bcl, and Pik3 series genes. Network pharmacology analysis proved that WZYZD can ameliorate OLI through BCL-2 and PI3 K-AKT signaling pathways. The immunofluorescence assay of BCL-2 and SPATA18 proved the aforementioned results. The potential mechanism of WZYZD in treating OLI mainly involved recruiting methyltransferase DNMT3 A, PIWIL1, PRMT5, and SETDB1 and increasing the methylation degree of Spata, Bcl, and Pik3 series genes.