The tablets make complicated and constant track movement with easy and smooth tur n frequent exchanging in a clean and closed drum of the film coating machine. The coating mixed round in the mixing drum are sprayed on tableds through the spray gun at the Inlet un action of the peristaltic pump. Meanwhile under the action of air exhaust and negative pressure 100, 000 clean hot air supplied by the air exhaust cabinet is exhausted from the fan at the sieve meshes through tablets. So these coating mediums on the surface of tablets get dry forming a coat of firm, fine and smooth film. The whole process is finished under the control of PLC.