Temperature fluctuations caused by hot asphalt paving on bridge structures represent a transient process that is challenging to monitor precisely. In order to investigate the temperature field of steel-concrete composite beams during asphalt high-temperature paving. By combining field measurements and finite element numerical simulations, the temperature distribution pattern of steel-concrete composite beams under asphalt high-temperature paving was investigated. A predictive formula for vertical temperature differences caused by asphalt high-temperature paving was proposed by utilizing a parameter analysis method. The research results indicated that the influence depth of asphalt high-temperature paving on steel-concrete composite beams mainly occurred within a range of 0.5 m and formed a large vertical temperature gradient. The vertical temperature difference pattern can be approximated by an exponential function, while the horizontal temperature difference pattern can be approximated by a sine function. The maximum vertical temperature difference is mainly influenced by the initial temperature of the beam T0, the thickness of the intermediate layer d, and the temperature of the asphalt mixture Ts. The calculated results from the proposed vertical temperature difference prediction formula are consistent with existing research. Provided a reference for studying the temperature distribution of steel-concrete composite beams during asphalt hot-mix paving.