With　the　aim　of　resolving　the　threshold　voltage　drift　problem　of　the　silicon　carbide　metal-oxide-semiconductor　field-effect　transistor　(SiC　mosfet),　which　is　caused　by　traps,　this　article　presents　a　study　of　the　laws　for　the　different　traps　that　affect　threshold　voltage　drift　and　also　clarifies　the　details　of　the　trap　that　leads　to　the　SiC　mosfet　threshold　voltage　drift.　First,　based　on　use　of　the　transient　current　method　for　trap　characterization,　we　eliminate　the　interference　from　the　SiC　bulk　traps,　and　the　time　constant　spectrum　of　the　gate　oxide　trap　is　then　obtained　accurately.　Second,　the　effects　of　the　different　traps　on　the　threshold　voltage　are　studied　by　filling　or　releasing　the　charges　from　traps　with　different　time　constants.　The　main　trap　time　constant　that　leads　to　the　SiC　mosfet　threshold　voltage　drift　is　revealed　to　be　300　ms,　whereas　the　other　trap　only　affects　the　current　and　hardly　contributes　to　the　threshold　voltage　drift.　Finally,　based　on　the　activation　energies　of　the　different　traps,　it　is　inferred　that　the　trapping　mechanism　of　the　traps　are　the　trap-assisted　tunneling　effect　and　the　hot　electron　emission　effect,　and　the　corresponding　trap　types　are　identified　as　the　oxide　trap　and　the　interface　trap,　respectively.