The invention discloses a high-temperature SiC JFET device based on a carbon-based composite electrode. The device comprises an N<+> substrate, an N<-> drift region, an N channel region, a P<+> grid region, an N<+> source region, a source electrode, a drain electrode and a gate electrode. The source electrode is formed by a first carbon-based material layer, a first metal layer and a second layer in a composite manner. The drain electrode is formed by a third carbon-based material, a third metal layer and a fourth metal layer. The gate electrode is formed by a second carbon-based material layer, a fifth metal layer and a sixth metal layer in a composite manner. The thickness of the N- drift region is 9.5[mu]m, the width is 7[mu]m and the doping density is 6.5*10<15>cm<-3>. The depth of the N channel region is 2.1[mu]m, the width is 1.6 [mu]m and the doping density is 6.5*10<15>cm<-3>. The doping density of the P+ grid region is 1*10<18>cm<-3>. The doping density of the N+ substrate is 6*10<18>cm<3>. The doping density of the N+ source region is 2*10<18>cm<-3>.The device has high heat stability and excellent conduction characteristics, heat radiation can be effectively improved, and junction temperature of the device can be reduced, so the device can stably and reliably work at a high temperature.