Preparation method of high-specific-activity urofollitropin

The invention relates to a preparation method of high-specific-activity urofollitropin, which comprises the following steps: adding a Tris-HCl equilibrium liquid with the pH value of 7.4 into low-purity menotrophin, passing through an anti-luteinizing-hormone antibody gel column, purifying and concentrating; sequentially carrying out anion-exchange chromatography, cation-exchange chromatography and blue sepharose dye affinity chromatography; collecting the washing liquid, and detecting washing liquid with a 280nm ultraviolet spectrophotometer; and when the OD (optical density) value is 0.002, collecting the washing liquid, purifying, concentrating, precipitating with absolute ethanol, and dehydrating to obtain the high-specific-activity urofollitropin of which the specific activity is higher than or equal to 10000 international units/mg protein. The preparation technique provided by the invention is simple and convenient to operate; the specific activity of the prepared urofollitropin is higher than or equal