As　the　research　on　the　3rd　generation　semiconductor　goes　further,　SiC　wafer　has　gained　popularity　in　the　market,　because　its　distinctive　properties　allows　it　to　overcome　the　limitations　of　Si　wafer,　which　enables　SiC　to　contribute　to　the　breakthrough　in　a　number　of　areas.　The　one-dimensional　polymorphism　of　SiC　means　that　SiC　with　different　polytypes　share　the　same　tetrahedral　arrangement　of　Si　and　C　atoms　but　differ　in　stacking　sequences.　In　this　study,　molecular　dynamics　(MD)　method　is　adopted　to　study　the　nano　grinding　process　of　3C-SiC　and　4H-SiC,　and　the　performance　parameters　of　the　two　during　the　grinding　process　will　be　discussed　in　order　to　explore　the　functional　differences　and　give　reference　for　the　application　of　SiC　in　various　scenarios.　The　result　indicates　that　SiC　grinding　process　is　the　plastic　removal　process　of　materials,　and　the　crystal　structure　of　surface　atoms　becomes　amorphous　structure　after　grinding　process.　Higher　cutting　speed　can　make　the　material　more　ductile　and　easier　to　be　removed.　It　also　leads　to　better　work　surface.