The invention discloses a preparing method of gastrodia-tuber decoction pieces. The preparing method mainly includes the steps of cleaning, fumigating, slicing, freezing, drying and the like. According to the gastrodia-tuber decoction pieces prepared with the method, sulfur is not adopted for fumigation in the whole processing process, slow fire processing is also avoided, the defect that sulfur is adopted for fumigation in the prior art is overcome, freezing and drying technologies are adopted, the effects of sufficient drying, mold preventing and quality guaranteeing are achieved, and it isguaranteed that effective ingredients of gastrodia tubers do not run off to the maximum degree; meanwhile, the gastrodia tubers are fumigated through self-made rhizoma chuanxiong liquid, and the medical effects of extinguishing wind to arrest convulsion, repressing liver yang, dispelling wind, removing obstruction in the meridians, treating dizziness, the intermittent headache, the headache, limbnumbness and the like of the gastrodia tubers are further improved.