Operational parameter variations significantly influence the internal temperature fluctuations of bushings. To develop a high-fidelity simulation model for real-time temperature changes in RIP bushings influenced by multiple parameter variations, this paper presents a model for the internal temperature distribution of RIP bushings considering external environment changes, oil temperature, and load rate. The results show that the highest temperature in RIP bushings is located in the lower part of the central current-carrying rod. Additionally, the increase in internal hot spot temperature lags behind the external environment changes. Because the lower end of the bushing is immersed in transformer oil, which has poor heat dissipation capability, there is a strong correlation between the hot spot temperature changes of the bushing and the oil temperature. These findings provide both theoretical and practical foundations for optimizing the design of RIP bushings. The research findings provide certain references for the operation and maintenance of dry-type bushings.