The invention which belongs to the traditional Chinese medicinal piece field concretely relates to an ultrafine traditional Chinese medicinal granule piece and a preparation process thereof. The invention which aims at present granulation processes and devices, small viscosity of traditional Chinese medicines, and the defects of irregular shape, easy moisture absorbing and bad fluidity of prepared granules provides a new production process which allows the ultrafine traditional Chinese medicinal granule piece with regular shape and good fluidity to be prepared from the small viscosity traditional Chinese medicines. The preparation process comprises the following steps: crushing the traditional Chinese medicines until the crushed traditional Chinese medicines can pass a 80-100 mesh sieve, processing according to a routine method, and crushing the traditional Chinese medicines to 400-1200 meshes; preparing a soft material; granulating by adopting a compression granulator; and drying the granules. The granule piece of the invention, which is prepared through crushing, processing and re-crushing, allows the traditional Chinese medicines to be uniformly and thoroughly processed, and the granule piece obtained through granulating and shaping the small viscosity traditional Chinese medicines by strong extruding force of the compression granulator has the advantages of regular shape, good visibility, small specific surface area, difficult moisture absorbing, and good fluidity, and can satisfy clinical medicine demands.