To investigate the impact of temperature on axial stress in large-span concrete variable-section continuous beam bridges under various wind speed fields, a method was proposed to calculate vertical temperature gradients separately based on inconsistent deck slab thickness and simulate lateral fluctuating wind speed fields using the spectral method. Firstly, vertical temperature gradient variations and their depths were calculated by employing the concrete heat-conduction equation, daily maximum and minimum temperatures, and deck slab thickness of the variable-section continuous beam bridge. Secondly, bridge modeling was performed using MIDAS Civil, and ZKH standard static live loads were simulated to represent moving train loads. Finally, static array wind loads and pulsating wind loads were applied to the bridge. The results indicate that the axial stresses in the left and right lanes obtained from the proposed method, which uses vertical temperature gradients and their depths derived from the concrete heat-conduction equation, daily temperature extremes, and bridge deck slab thickness, are larger compared to existing studies. Under the same wind speed field model, the harm to the bridge is greatest under gradient heating, followed by gradient cooling, while no temperature change results in the least impact. When the bridge is subject to the same temperature model, both the axial stress values and amplitudes of the bridge under pulsating wind loads are larger and more severe than those under no wind or static wind conditions, posing greater hazards to the bridge. The research findings can provide references for the structural design and safe operation of large-span concrete variable-section continuous beam bridges.