A synthetic method for 2-methyl propioric-[(2S)-4-(2,4-diflurophenyl)-2-hydroxymethyl-4-pentene-1-yl] ester includes the steps that 3-chloro-1,2-propylene glycol and 1,3-difluorobenzene are mixed, react for 6-10 h after a catalyst is added and react for 2-4 h after being heated to the temperature of 50-70 DEG C; the product is added into a hydrochloric acid solution at the temperature of 5-minus 5 DEG C, dichloromethane is used as an extraction agent to conduct extraction for 3-5 times, and extract liquor is washed once with a NaHCO3 solution, water and saturated saline solution; anhydrous Na2SO4 is dried and filtered, and dichloromethane is evaporated to obtain 1-chloro-2-(2,4- diflurophenyl)-3-propyl alcohol; 1-chloro-2-(2,4- diflurophenyl)-3-propyl alcohol and potassium hydrogen sulfate are added into chlorobenzene, and heating reflux is conducted for 10-16 h; the product is washed to be neutral, dried with anhydrous Na2SO4 and then filtered, the distillation product is dissolved in DMSO, diethyl malonate and hydroxide are added for reacting, the obtained product reacts with lithium chloride and sodium borohydride to obtain a product, and the product is dissolved in methylbenzene, sodium bicarbonate, Novo SP 435 esterifying enzyme and isobutyric anhydride are added for reacting; the target product is obtained through washing, crystallizing and drying.The synthesis path is as follow (see the path in the description).