NOVELTY - Cyclopropane carboxylic acid, methanol, and acid catalyst are esterified to obtain methyl cyclopropane carboxylate and water. Methanol and water are evaporated and dehydrated, and methanol is recycled. The catalyst is removed, and methanol is distilled. The obtained ester, biphenylylmethyl carbinol, and a basic catalyst are transesterified to obtain bifenthrin and methanol. The materials are distilled to remove methanol and dissolved in an organic solvent. The crystals are separated out and centrifuged to obtain bifenthrin product.    USE - Preparation of three-waste-free bifenthrin (claimed).    ADVANTAGE - The method enables simple preparation of bifenthrin with high yield; a great number of harmful wastes are not generated in the preparation process, and the separated water, methanol and organic solvent are all recycled so that no environment pollution is caused.    DETAILED DESCRIPTION - Cyclopropane carboxylic acid, methanol, and a solid or liquid acid catalyst are added to a reactor in a molar ratio of 1:(3-9):(0.01-0.03) and esterified at 60-80 degrees C, to obtain methyl cyclopropane carboxylate and water. Methanol and water are evaporated and dehydrated, and methanol is recycled to the reactor. The catalyst is removed, and methanol is distilled at 0.07-0.095 MPa and 30-70 degrees C. The liquid acid is sulfuric acid, phosphoric acid, or boric acid. The solid acid contains solid sodium bisulfate or activated carbon, with silica gel or white kaolin as carrier. The obtained ester biphenylylmethyl carbinol, and a basic catalyst are mixed in a molar ratio of 1:(0.5-2):(0.003-0.01), and transesterified at 0.065-0.08 MPa and 50-70 degrees C to obtain bifenthrin and methanol. The materials are distilled to remove methanol and dissolved in an organic solvent. The crystals are separated out at -5 degrees C to 5 degrees C and centrifuged to obtain bifenthrin product. The mother liquid is distilled to separate the organic solvent, and the organic solvent and residual liquid are recycled. The basic catalyst is sodium hydroxide, potassium hydroxide, sodium cyanide, potassium cyanide, sodium alkoxide, and/or potassium alcoholate.