The　effect　of　anisotropy,　which　is　crucial　for　manufacturing　single　crystals,　was　investigated　in　this　study　by　performing　nanoindentation　experiments　on　the　Si/C　plane　of　single　crystal　4H-SiC　with　the　edge　of　Berkovich　indenter　toward　with　two　different　crystal　orientations　of　[112¯0]/[11¯00].　On　the　Si　plane,　when　the　edge　was　toward　crystal　orientation　[112¯0]/[11¯00],　the　indentation　hardness　is　39.37/39.77　GPa,　the　elastic　modulus　is　528.16/513.88　GPa,　and　the　fracture　toughness　is　3.286/2.609 MPa·m1/2.　On　the　C　plane,　when　the　edge　was　toward　crystal　orientation　[112¯0]/[11¯00],　the　indentation　hardness　is　43.66/41.91　GPa,　the　elastic　modulus　is　522.24/546.54　GPa　and　the　fracture　toughness　is　2.826/2.705 MPa·m1/2.　At　the　same　time,　the　Vickers　hardness　crack　induction　method　was　used　to　calculate　the　fracture　toughness,　regardless　of　the　Si　or　C　plane,　the　fracture　toughness　value　of　the　crystal　orientation　[112¯0]　is　generally　greater　than　that　[11¯00].　Molecular　dynamics　(MD)　indentation　simulations　were　carried　out　with　the　indenter　edge　facing　different　crystal　directions　of　the　Si　plane.　There　is　obvious　anisotropy　in　the　depth　of　the　amorphous　atomic　layer,　the　number　and　proportion　of　dislocation　nucleation,　and　the　shear　strain　expansion.　Although　microscratch　experiments　combined　with　the　analysis　of　scratch　variables　and　the　optical　topography　of　scratches,　it　is　concluded　that　the　scratch　deformation　damage　towards　the　crystal　orientation　[11¯00]　is　smaller.　This　study　can　provide　theoretical　guidance　for　the　ultra-precision　machining　of　the　anisotropy　of　4H-SiC　crystal　structure.　©　The　Author(s),　under　exclusive　licence　to　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature　2025.