Abstract: SiC IGBT devices are more suitable for high-voltage and high-current applications due to their excellent performance. Because of the limitations of the existing manufacturing process, they have not been able to achieve large-scale production. In contrast, hybrid SiC IGBT can achieve better efficiency and cost optimization now. In order to study the performance of hybrid SiC IGBT, we proposed a method for establishing a Saber-based variable-parameter transient electrothermal coupling model in which the influence of temperature is taken into consideration. First, the temperature sensitivity of different parameters of the device was analyzed, and the temperature characteristics of each temperature-sensitive parameter were obtained. Then, from a theoretical point of view, the influence of junction temperature changes on the transient process dU_CE/dt and dI_C/dt of hybrid SiC IGBT was analyzed, which reduced the introduction of additional parameters of mathematical fitting methods. Based on the analysis, a simulation model was established and a physical platform was built. Under different initial ambient temperature conditions, with the increase of the working time of hybrid SiC IGBT devices, the change law of transient characteristics and the law of junction temperature rise were tested. Finally, the simulation results of the established variable-parameter transient electrothermal coupling model were compared with the actual results. The two have a high degree of agreement, which verifies the accuracy of the model, and provides the dynamic performance analysis and temperature change law when the hybrid SiC IGBT is applied in the actual engineering reference.