The invention relates to a growth method of a large-sized silicon carbide polycrystalline ceramic adjustable in electrical resistivity. A silicon carbide raw material is contained by adopting a graphite crucible, the graphite crucible is composed of a graphite crucible top cover and a graphite crucible body, the inner surface of the graphite crucible is provided with a carbon film layer, the silicon carbide raw material is put in the graphite crucible body, the graphite crucible top cover is put on, the graphite crucible body is put in a growth furnace, the bottom and/or the lower portion of the graphite crucible body is located in a heating zone to make the temperature at the bottom of the graphite crucible body higher than that of the graphite crucible top cover, and a silicon carbide polycrystalline ceramic material grows on the surface of the carbon film layer by adopting a physical gaseous phase transmission method or a high-temperature chemical vapor deposition method. The growth method is simple, and the silicon carbide polycrystalline ceramic is more excellent in performance, better in uniformity, better in compactness, higher in purity and better in thermal conductivity compared with a traditional silicon carbide ceramic.