The invention relates to a method for synthesizing an indole derivative shown in the formula (III) (please see the specification). The method includes the steps that in a solvent and inertia gas atmosphere, when a catalyst, a nitrogen-containing ligand, an acid accelerator and KF exist, a compound in the formula (I) (please see the specification) and a compound in the formula (II) (please see the specification) are reacted, aftertreatment is carried out after the reaction is completed, and therefore the compound in the formula (III) is obtained, wherein R1 is selected from H or halogen, and R2 is selected from H, C1-C6 alkyl, C1-C6 alkoxy or halogen. According to the method, as a proper substrate, the proper catalyst, the proper nitrogen-containing ligand, the proper acid accelerator, the proper KF, the proper solvent and the like are comprehensively selected and cooperated, the range of the substrate is expanded accordingly, the indole derivative can be obtained with the good yield, the method has good application prospects and research value in the field of organic chemistry synthesis, and a brand new method is provided for synthesis of the compound.