The emergence of high-energy lithium-ion batteries has raised an urgent need for crucial electrode materials, particularly for anode. Nevertheless, a significant obstacle hindering the actual application of these technologies is due to the occurrence of capacity degradation during cycles and subpar rate performance. A hydrothermal approach is used to easily synthesize bismuth oxide nanocomposite (Bi2O3@Ti3C2) by establishing chemical bonding. Single-crystal bismuth oxide (Bi2O3) nanoparticles, averaging 80 nm in size, are evenly distributed at Ti3C2 nanosheets surface. In comparison to agglomerated pristine Bi2O3 nanoparticles, the composite nanostructure enhances porosity and electrical conductivity of the composite anode material. The electrochemical efficiency of the Bi2O3@Ti3C2 nanocomposite material is remarkable, as evidenced by its initial cycling capacity of 704 mAh g−1 at 200 mA g−1 current density and a capacity retention of 598 mAh g−1 over 100 charge/discharge cycles. The high electrical conductivity of Ti3C2 MXene nanosheets significantly improves the overall electrochemical properties of the Bi2O3@Ti3C2 nanocomposite material. Density functional theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) measurements have further confirmed that charge transfer to active Bi2O3 nanoparticles is efficiently promoted within such composite material during lithiation/delithiation processes. The nanocomposite of Bi2O3@Ti3C2 exhibits significant potential for electrochemical energy storage applications.