This study simulates thermal conductivity via a carrier scattering mechanism and the related parameters are obtained based on first principles for intrinsic and doped silicon carbide (SiC) over a temperature range of 300-1450 K. The theoretical analysis results show that the thermal conductivity decreases with increasing temperature along each orientation for both cubic SiC (3C-SiC) and doped SiC. Compared with traditional calculations, the thermal conductivity of doped SiC is larger than that of intrinsic SiC in the high-temperature region. In particular, the n-type thermal conductivity is higher than the p-type thermal conductivity because of the scattering probability between electrons and the ionization impurity increasing with the temperature. Our studies are important to a further understanding of thermal transportation.