In　this　article,　a　new　online　temperature　measurement　method　for　silicon　carbide　power　metal-oxide-semiconductor　field-effect　transistors　(mosfets)　is　proposed　that　uses　the　linear　relationship　between　the　drain-source　current　(I-ds)　and　the　temperature　of　power　electronic　devices.　The　temperature-sensitive　characteristics　of　the　transfer　characteristic　curve　of　these　mosfets　are　studied.　The　results　show　that,　under　different　applied　gate　voltages,　the　effects　of　temperature　on　the　change　in　the　I-ds　are　different;　under　the　same　gate　voltage,　the　drain-source　current　of　each　device　maintains　a　good　linear　relationship　with　the　temperature,　which　can　be　used　to　perform　the　accurate　junction　temperature　measurements　of　power　mosfets.　Based　on　this　characteristic,　by　superimposing　a　pulse　on　the　gate,　characterizing　the　instantaneous　current　produced　by　this　superimposed　pulse,　and　combining　this　characteristic　with　the　relationship　between　the　I-ds　change　and　temperature,　detection　of　the　device＇s　operating　temperature　under　actual　working　conditions　is　realized.　Furthermore,　a　related　circuit　is　designed　to　reduce　the　influence　of　changes　in　the　electrical　bias　on　the　system　stability　during　temperature　measurements.　In　addition,　the　measurement　results　are　verified　via　infrared　thermal　imaging,　and　the　results　show　that　the　proposed　method　has　good　practicability.