The invention provides a sublimator which is suitable for utilizing sublimation property of material to prepare chemicals and has the advantages as follows: the sublimation speed is high, the production efficiency is high, material cannot be hardened during the sublimation process, and energy utilization ratio is improved greatly. The sublimator comprises an inner housing and an outer housing, wherein, heating elements are coated with the inner housing; the inner housing is coated with the outer housing; a material filling port and a material sublimation gas outlet are formed on the outer housing; a ring-shaped channel used for holding material to be sublimated is formed between the inner housing and the outer housing; a transmission mechanism that leads the material to be sublimated to flow along the ring-shaped channel is arranged in the ring-shaped channel; the transmission mechanism comprises bearings, gears, chains and shovel plates; the shovel plates are used for shoveling and stirring material to be sublimated; transmission chains that surround the outer side surface of the inner housing in the circumferential direction are respectively arranged on the front end surface and the rear end surface of the inner housing; each transmission chain is driven by the two gears; the two bearings that are transversely arranged at two ends of the end surface of the inner housing are sheathed with the gears respectively; in addition, the plurality of shovel plates used for shoveling and stirring material to be sublimated are distributed along the ring-shaped channel at intervals, and are connected with the transmission chains.