With the development of new energy industry, there is a trend to increase bus voltage. The existing 1700 V device cannot meet the application of 1500 V bus voltage well. The new 2000 V device is a potential better choice. The avalanche and short-circuit characteristics of 2000 V silicon carbide metal oxide semiconductor field effect transistor (SiC MOSFET) were tested and compared with those of 1700 V SiC MOSFET. This paper also compared the effects of 1200 V devices and 2000 V devices used in practical circuits. A boost circuit based on 2000 V SiC MOSFET and a dual-boost circuit based on 1200 V SiC MOSFET were built, and their circuit waveform, efficiency and temperature were compared. The comparative study on reliability and application features of SiC MOSFET has reference significance for the development of SiC MOSFETs that meet application requirements.