The invention provides a seed crystal processing method for growing high-quality silicon carbide crystals. According to the method, compact silicon carbon yttrium or yttrium carbide film coatings are formed on the back of the growth face of a seed crystal to inhibit back evaporation of the seed crystal, and the high-quality silicon carbide crystals are grown. The distillation process of the backs of the silicon carbide crystals is directly inhibited due to the high temperature resistance of the coatings and the specialty of the material composition, the flat hexagonal defect caused by back evaporation in the crystal growth process is effectively eliminated, the quality of the silicon carbide crystals is greatly improved, and the yield of the silicon carbide crystals is greatly raised.