As the important accessory device of the power transformers, high-voltage bushing can undergo changes in their internal insulation state due to temperature variations under long-term operating conditions, resulting in localized overheating. This further affects the distribution of electric fields in the bushing, and even leads to local electric field distortion, which seriously threatens the safe operation of the bushing. At present, the simulation calculation of dynamic temperature distribution has not been carried out in the research on temperature distribution in the bushing. Meanwhile, the influence of current-carrying capacity and air convection heat transfer coefficient on temperature distribution has not been clarified. To address this issue, this paper constructed a proportional finite element simulation model based on the actual structure of a 220 kV oil-immersed bushing and conducted the simulation analysis on the dynamic temperature distribution in the bushing. The axial and radial temperature distributions of the bushing were simulated considering different current-carrying capacities and air convection heat transfer coefficients. Finally, this paper clarified the influence law of current-carrying capacity and conversion coefficient on dynamic temperature distribution, which can provide theoretical guidance for structural optimization, operation and maintenance, and replacement of high-voltage oil-paper bushings.