NOVELTY - Preparation of ivermectin adding chlorocarbonic acid diene propyl ester and abamectin in the presence of an organic base in inert solvent, adding allyl chloroformate, adding dimethyl sulfoxide and the oxidant in the presence of an organic base, oxidizing to a ketone carbonyl group, decomposing, desolventizing, adding borohydride as a reducing agent in an inert solvent in the presence of a palladium catalyst, adding alcohol, crystallizing ivermectin, adding alcohol in an inert solvent at a reaction pressure, and performing in an inert gas atmosphere.    USE - Preparation of ivermectin (claimed).    ADVANTAGE - The ivermectin is economically and efficiently prepared with high yield.    DETAILED DESCRIPTION - Preparation of ivermectin adding chlorocarbonic acid diene propyl ester and abamectin in the presence of an organic base in inert solvent, adding allyl chloroformate, 5-allyl carbonate avermectin and 5-hydroxyl groups at -40 degrees C to 40 degrees C for 1-10 hours, adding dimethyl sulfoxide and the oxidant in the presence of an organic base, oxidizing to a ketone carbonyl group at -40 degrees C to 30 degrees C for 3-20 hours, adjusting the reaction solution to a concentration of 1-5% phosphoric acid and base to 6-8, placing to the water phase, decomposing, desolventizing, obtaining avermectin B2 23-bit ketone compounds, placing organic sulfonyl hydrazide in avermectin B2 23-avermectin compound and B2 23-bit sulfonyl hydrazone in an alcohol solution at 20-80 degrees C for 1-24 hours, adding borohydride as a reducing agent in an inert solvent in the presence of a palladium catalyst, adding alcohol, obtaining avermectin B2 23-bit sulfonylhydrazone, crystallizing ivermectin at 0-60 V for 1-20 hours, adding 2-20 volume% alcohol in an inert solvent at a reaction pressure, and performing in an inert gas atmosphere. The amount of the organic base is 2-6 times with respect to the number of moles of avermectin B2. The amount of allyl chloroformate avermectin B2 is 2-6 times. The amount of the oxidizing agent is 1-6 times. The amount of organic sulfonyl hydrazine avermectin B2 23-bit compound is 1-6 times. The amount of borohydride avermectin B2 23-bit sulfonyl hydrazone is 0.5-3 times.