Salvia miltiorrhiza, the anticancer properties of these components are multifaceted, encompassing the inhibition of tumor growth, prevention of the metastatic spread of cancer cells, enhancement of the sensitivity of cancer cells to chemotherapy and radiation therapy, and the suppression of angiogenesis, which is crucial for tumor growth and survival. In the context of our recent study, we have discovered that tanshinone I, one of the active components of Salvia miltiorrhiza, possesses the ability to inhibit the proliferation of ovarian cancer cells, both in laboratory settings and within living organisms. To further understand the molecular mechanisms behind this effect, we conducted a comprehensive transcriptomic analysis. Our findings indicated that tanshinone I exerts its inhibitory action by downregulating the expression of genes associated with glycolysis. Specifically, tanshinone I decreased the expression of glycolysis-related genes such as HK2 (hexokinase 2), PFK (phosphofructokinase), ENO2 (enolase 2), and LDHA (lactate dehydrogenase A). Inhibiting lactate production by tanshinone I application reduced the level of histone H3 lysine 18 lactylation (H3K18la), which reduced the expression of tumor-associated genes, such as TTK, PDGFRβ, YTHDF2 and RUBCNL. In addition, tanshinone I alleviated the immunosuppressive tumor microenvironment. In summary, tanshinone I blocks glycolysis to regulate histone H3 lysine 18 lactylation (H3K18la), which inhibits ovarian cancer cell growth, revealing the anticancer mechanism of tanshinone I.