The application of SiC devices in inverters makes heat dissipation design a key to high frequency inverters. To this end, this paper proposes a SiC three-phase inverter thermal design method based on PLECS software. Firstly, the calculation model of the total loss of SiC inverter is established. The thermal resistance is equivalent and the thermal resistance of the radiator is analyzed. Based on the relationship between geometry and characteristic parameters, a SiC MOSFET inverter with a power of 10 kW is applied. The thermoelectric system of SiC inverter is built in PLECS software. The loss of SiC MOSFET is analyzed by simulation. Source, designed the appropriate heat sink thermal resistance value, designed the heat sink according to the heat sink thermal resistance model and completed the test in the experiment, which verified the rationality and correctness of the thermal design method.#$NLKeywords: PLECS; SiC; Inverter; Cooling