The　widespread　application　of　bulk　silicon　carbide　in　pressure　sensing　has　been　largely　limited　by　the　slow　etching　rate　of　traditional　micromachining　processes.　This　paper　proposes　a　piezoresistive　bulk　4H-SiC　pressure　sensor　with　diaphragm　which　has　controllable　thickness　realized　by　femtosecond　laser.　A　modified　stress　model　was　established　by　finite　element　analysis　to　fit　the　SiC　circular　diaphragm　prepared　by　laser　micromachining.　The　test　results　proved　that　the　fabricated　sensor　with　diaphragm　thickness　of　$60　\mu　\text{m}$　had　sensitivity　of　1.42　mV　$/\text{V}/$　MPa　under　the　applied　pressure　of　up　to　5　MPa　at　room　temperature.　Small　hysterisis　error　of　0.17　%/FSO　and　nonlinearity　of　0.20　%　$/$　FSO　was　achieved.　The　sensor　was　able　to　work　in　a　broad　temperature　range　with　the　temperature　coefficient　of　sensitivity　of　-0.23%　FSO/°C　at　-50　°C　and　-0.10%　FSO/°C　at　300　°C.　The　dynamic　response　results　exhibited　that　the　resonance　frequency　of　the　sensor　was　60.11　kHz　and　the　rise　time　was　$18　\mu　\text{s}$.　The　SiC　pressure　sensor　also　had　the　noise-limited　resolution　of　0.42　kPa　and　the　dynamic　range　of　44.9　dB.　The　research　demonstrates　the　prospect　of　employing　the　femtosecond　laser　technology　to　prepare　bulk　SiC　pressure　sensors　for　extreme　temperature　environment.　©　2001-2012　IEEE.