This study focuses on investigating the heat transfer characteristics of large-diameter bridge energy piles through field tests, aiming to examine the heat exchange rate and temperature distribution of a full-scale large-diameter bridge energy pile and surrounding soil. Additionally, three-dimensional numerical models of large-diameter bridge energy pile are developed and validated by comparing field measurements with simulation results. With the validated model, a parameter sensitivity analysis is conducted to explore the influence mechanism of convective heat exchange between bridge piers and surrounding air on the heat transfer characteristics of large-diameter energy pile. The results indicate that the heat exchange rate of large-diameter bridge energy pile can reach -222.28 W/m, which is approximately 1.5 to 3.9 times higher than that of conventional energy piles. However, the larger diameter of the pile leads to uneven temperature distribution across the cross section. Specifically, the temperature near the heat exchange tubes is significantly higher (around 3℃) compared to the temperature at the central axis position. Furthermore, it is observed that in low-temperature conditions, the convective heat exchange between bridge piers and surrounding air causes a decrease in the temperature of the pier, thereby increasing the heat exchange rate of the bridge energy pile under summer mode. When the surface of the pier transitions from natural convection (air flow rate of 0 m/s) to forced convection (air flow rate of 5 m/s), the heat exchange rate of the bridge energy pile increases by approximately 22 W/m.