In recent years, glass anodes have been widely studied. However, self‐crystallization often occurs during glass preparation, which leads to a reduction in the cycle stability of the glass anode. In this work, SnO–P2O5–MnO2 glass anode materials were prepared using the melt‐quenching method. By increasing the concentration of MnO2, the specific capacity (after 800 cycles) of the glass anode was increased by 62%, from 234.9 to 381.3 mAh g−1. The result indicates that the introduction of MnO2 makes the glass structure more compact and suppresses the glass's ability of self‐crystallization, which is beneficial for the long‐cycle performance of lithium‐ion batteries. In addition, with the introduction of MnO2 in glass, manganese–tin synergistic discharge disperses the internal stress during the alloying process, which further enhances the cycling stability of the glass anode. This research is to propose a new reference for improving the cycle life and specific capacity of glass anode materials.