The invention provides a preparation method for polysubstituted indole derivatives. The preparation method comprises employing alkynyl-terminated hydrocarbon, a halogenated aniline derivative and a disulfide as initial raw materials, using an amino acid as an additive and a copper salt as a catalyst, performing a coupling-tandem one-pot reaction in an organic solvent under an alkali-added condition, so as to obtain the corresponding polysubstituted indole derivative, wherein the catalyst is CuX, and X is iodine or bromine. According to the technical scheme, the method for synthesizing the polysubstituted indole derivatives through one-pot process is developed on the basis of a method for synthesizing 2-substituted indole through copper catalysis. The method does not employ an expensive palladium catalyst easily polluting environment. The method enables alkynyl-terminated hydrocarbon, one halogenated aniline derivative and one disulfide to have the coupling-tandem one-pot reaction under a relatively mild condition, is simple in technology and strong in operationality, and possesses industrial application prospect.