The invention discloses a refining method for
tetracycline. The method comprises the following steps: (1) adding crude
tetracycline into an acid
solvent, and adding an acid precipitant and
borax for dissolving to obtain a mixture A; (2) adjusting the pH of the mixture A to 1.2-2.8, standing the mixture A, and filtering the mixture A to obtain filtrate A; (3) adding
zinc sulfate,
potassium ferrocyanide and
active carbon into the filtrate A to obtain a mixture B, standing the mixture B, and filtering the mixture B to obtain filtrate B; (4) performing
ultrafiltration on the filtrate B to obtain filtrate C, adjusting the pH of the filtrate C to 4.5-5.0, standing the filtrate C, and filtering the filtrate C to obtain a
filter cake A; (5) taking the
filter cake A out, dissolving the
filter cake A by using the acid
solvent, adjusting the pH of the dissolved filter cake A to 4.5-5.0, standing the dissolved filter cake A, and filtering the dissolved filter cake A to obtain a filter cake B; and (6)
drying the filter cake B in vacuum to obtain refined
tetracycline. The refining method disclosed by the invention has the advantages of high product yield, high product purity, easiness and feasibility in operation, need of simple equipment, adoption of cheap and readily-available raw materials and low cost, and is suitable for large-scale industrial production.