Purification method of clevidipine butyrate

The invention discloses a purification method of clevidipine butyrate The purification method comprises following steps: step A, an ethanol solution of clevidipine butyrate is prepared, and organic impurities are removed by crystallization purification; step B, crystals purified by ethanol are dissolved in acetonitrile, and then are precipitated by adding water so as to remove a large amount of inorganic impurities; and step C, the crystals purified by acetonitrile are dissolved in an ethanol solution with a concentration of 50 to 90% so as to remove a small amount of inorganic impurities. The products are dissolved completely by mixing the poor solvent with the good solvent so as to realize complete purification; the purity of clevidipine butyrate reaches 99.5%; and arsenic, lead and chloride indexes are all much lower than that of standards.