Abstract：More than 99% purity of liquid crystal intermediate of 4-ethoxy-2,3-difluoroacetophenone was synthesized via Friedel-Crafts reaction with 2,3-difluoroethoxybenzene and acetyl chloride as starting materials. The target compound was characterized by 1HNMR、IR and GC-MS. The results of condition experiments showed the reaction effect was best with aluminium chloride as catalyst, dichloromethane as reaction solvent, when 2,3-difluoroethoxybenzene /aluminium chloride/acetyl chloride was 1/1.14/3,the reaction temperature was -10~-5 ℃ and the reaction time was 1 h. And the mechanism of Friedel-Crafts reaction and the generation cause of the by-products was speculated.