Its preparation method is based on ethyl p-ethoxyphenylacetate as raw material, and diethyl oxalate undergoes an addition reaction in the presence of sodium ethoxide, and the obtained product reacts in acetic acid to generate 4-ethoxy-2-carbonylcarboxylate ethyl phenyl acetate, and then reacts with formaldehyde to generate 4-ethoxy-2-methylenephenylacetate, which is then cyclically combined with chloroform in an alkaline solution in the presence of phase transfer, 2-Dichloro-1-(4-ethoxyphenyl) cyclopropanecarboxylic acid ethyl ester, saponification, acidification, to obtain the corresponding cyclopropanecarboxylic acid.