Preparation method of silicon carbide ceramic

The invention provides a preparation method of silicon carbide ceramics, and belongs to the technical field of silicon carbide ceramics. The preparation method of the silicon carbide ceramic comprises the steps of silicon carbide modification, material mixing, spray granulation, dry pressing molding and calcination. The step of modifying the silicon carbide comprises the steps of cleaning, silane treatment, graphene oxide pretreatment and modification; the silane treatment comprises the following steps: putting the silicon carbide particles subjected to acid pickling into an ethanol solution, adding Tween-80 for ball milling treatment, adding gamma-aminopropyltriethoxysilane after ball milling is finished, performing ultrasonic oscillation treatment, standing after ultrasonic treatment is finished, keeping the temperature at 68-74 DEG C and the standing time at 50-58 minutes, and drying after standing is finished. Silicon carbide particles subjected to silane treatment are prepared; according to the silicon c