The invention discloses a low-temperature foaming drying method of valnemulin hydrochloride. The method comprises the following specific steps: distilling a valnemulin hydrochloride aqueous solution at the temperature of 20 DEG C-50 DEG C at reduced pressure until water is evaporated; then adding a solvent for distilling and foaming; and adding a mixed solvent for azeotropic distillation until water is evaporated. The content of obtained valnemulin hydrochloride is 96% and above; and the obtained valnemulin hydrochloride is white or white-like crystal and has the water content of 1.0-2.5%. By using the method disclosed by the invention, the requirement of equipment is greatly reduced, the cost is low, and the obtained product has the advantages of good water solubility and storage stability.