Cultured meat (CM) is an emerging technology for meat production by the cultivation of muscle satellite cells. However, this technology faces a critical challenge: muscle satellite cells struggle to maintain their stemness during long-term culture, which severely limits their proliferation ability. Consequently, developing safe and effective additives to promote the growth of myoblasts has become a key focus of current research. This study evaluated three small molecules targeting different pathways, including SB431542 (Transforming growth factor-beta (TGF-β) inhibitor), MHY1485 (mechanistic target of rapamycin (mTOR) activator), and CHIR99021 (Glycogen synthase kinase 3beta (GSK3β) inhibitor). Comparative experiments revealed that CHIR99021 significantly outperformed others in promoting myoblast proliferation and enhancing myogenic differentiation, highlighting GSK3β inhibition as a promising strategy. Given that synthetic small molecules may not meet food-grade safety standards, we explored natural alternatives. Through molecular docking simulation screening, we found that natural polyphenolic compounds such as daidzein (Daid), epigallocatechin gallate (EGCG), genistein (Gen), and naringin (Nar) exhibit strong binding ability with GSK3β. Additionally, these natural polyphenols can stimulate myoblast proliferation by regulating the cell cycle, particularly by preventing the transition from the S phase to the G2/M phase. Mechanistically, Nar uniquely inhibited the GSK3β-mediated Wnt/β-catenin pathway, upregulating myogenic regulatory factors Pax7 and MyoD1. Thus, Nar can be utilized as a safe and effective additive in culture medium to replace CHIR99021, overcoming the challenge of in vitro expansion of myoblasts and laying a theoretical foundation for the application of natural polyphenols in the production of CM.