The invention provides a synthetic method of an acetylenic ketone compound shown in a formula (III). The synthetic method comprises the following steps: a compound shown in a formula (I), a compound shown in a formula (II) and an organic solvent are added to a reaction kettle in a nitrogen atmosphere, the mixture is heated to 40-50 DEG C and stirred and mixed for 10 min, then a catalyst and an additive are added, heat is preserved and stirring is performed for reaction for 3-5 h, and the compound shown in the formula (III) shown in the specification is obtained through posttreatment after the reaction, wherein R is H, a C1-C6 alkoxy group or halogen; Ar1 and Ar2 are independently selected from an unsubstituted phenyl group, a phenyl group with a substituent, an unsubstituted thienyl group or a thienyl group with a substituent respectively, and the substituent is a C1-C6 alkyl group or a C1-C6 alkoxy group. According to the synthetic method, the yield of a product is increased effectively by the aid of the synergistic effects of three components including the catalyst, the additive and the organic solvent, an excellent technological effect is obtained, and broad industrial application prospects and production potential are realized.