The invention relates to an automatic grinding and polishing system for a crystal blank. The automatic grinding and polishing system comprises a first rotation frame, a material loading station, a material unloading station, and at least one transferring mechanism; grinding stations and polishing stations are arranged around the first rotation frame; the first rotation frame can be rotated and positioned, and is provided with at least two machine heads; the transferring mechanism can pick up and place down a clamp and transfer the clamp among the material loading station, the material unloading station and the machine heads on the first rotation frame; the grinding stations are provided with grinding mechanisms; and the polishing stations are provided with polishing mechanisms. The invention also discloses auxiliary machinery used by the system. Through the technical scheme, the full-automatic grinding and polishing of a hemispherical inclined surface of the crystal blank can be realized, the grinding and polishing quality is guaranteed, the advantages of the conventional machine type are fully utilized, the complexity of the mechanism action is simplified, and the automatic grinding and polishing system is easy to manufacture and maintain.