The invention provides a ceramic slurry injection forming system. When a slurry injection device injects slurry into a plaster mold, a movable supporting pipe rises up from the bottom of the plaster mold while being subjected to slurry injection, so that the phenomenon that air is mixed in slurry due to mutual collision of the slurry can be avoided during slurry injection; meanwhile, a rotating part drives the plaster mold to rotate to enable the slurry in the plaster mold to be uniformly distributed; a slurry supplementation device supplements the slurry to the plaster mold, so that the phenomenon of unstable size and thickness of a product due to the fact that the plaster mold is not full of the slurry because of various reasons in the slurry injection device is avoided; a drying device enables the plaster mold to absorb the slurry for forming; a main pipe in a slurry extraction part is connected with a vacuum pump, so that residual slurry in the plaster mold can be extracted; a slurry throwing part drives the plaster mold to move, so that a little of slurry extracted from the bottom of the plaster mold is thrown to the inner wall of the plaster mold so as to be absorbed by the inner wall; and therefore, the ceramic slurry injection forming system provided by the invention is high in automation degree and high in product quality, and is relatively clean in production and high in production efficiency.