Using linear combination operator and perturbation method,the influences of electron spin on the properties of SiC is studied.Ground state energy E~+_0(E~-_0) that the spin quantum number is plus(minus) decreases linearly with the magnetic field B increasing.E~+_0 and E~-_0 are-76.24 meV at 0 T.E~+_0(E~-_0) is-68.50 meV(-71.39 meV) at 25 T.The ratio P~+_0(P~-_0) of spin energy to E~+_0(E~-_0) increases rapidly with B increasing.P~+_0 and P~-_0 are 0 at 0 T.P~+_0(P~-_0) is 0.627(0.453) at 20 T(25 T).The ratio P_2 of spin energy to Landau ground state energy is always 0.23.The ratio P_1(P_3) of spin energy to self-energy(energy of interaction between phonons) increases linearly with B increasing.P_1 and P_3 are 0 at 0 T.P_1(P_3) is 0.306(0.628) at 40 T(5 T).These data and results are helpful to design and develop spin field effect transistor,spin light-emitting diode,spin resonant tunneling device,etc.