SiC power device has developed into a leader in the field of high voltage power devices. However, the high density interface states at the interface between SiC and SiO2 restricts the electrical properties of the SiC. Although manufacturers have adopted different gate oxidation processes to improve the channel mobility of the inversion layer, the corresponding interface states simulation model is not provided. Besides, the various interface state energy level distribution model, given by the device simulation software, causes choice dilemma for the device-designers of power devices. Thus, this paper provided an distribution model of interface state energy level for SiC MOSFET device simulation based on actual process data and TCAD simulation software. In the aid of the given model combined with TCAD software simulation, the I-V curve obtained by the simulation basically coincided with the test curve of the actual product.