The invention belongs to the technical field of foods, and particularly relates to beef noodle thin soup and a preparation technology thereof. The beef noodle thin soup comprises main materials and auxiliary materials, and traditional Chinese medicines are also added. A specific preparation method of the beef noodle thin soup comprises the following steps of placing thoroughly-cleaned ox bones, thoroughly-cleaned beef, thoroughly-cleaned scallions and thoroughly-cleaned ginger in a pot together, putting water, and performing stewing for 20-30 hours so as to prepare thin soup; and adding the auxiliary materials namely star anise, Chinese cinnamon, cumin seeds, Chinese prickly ash, scallions, ginger, salt, gourmet powder, chicken essence, curry powder, and a spicy sauce to the made thin soup, and performing boiling over. The traditional Chinese medicines can also be added to the thin soup, namely radix codonopsis, raw radix astragali, bighead atractylodes rhizomes and glossy ganoderma are thoroughly cleaned, then dicing is performed, and the diced radix codonopsis, the diced raw radix astragali, the diced bighead atractylodes rhizomes and the diced glossy ganoderma are put into a gauze bag; and at the same time, the gauze bag is put in the thin soup for boiling over, so that the beef noodle thin soup is prepared.