The invention relates to a 2,3,4-tri-substituted pyrrole compound and a synthesis method and application thereof. Particularly, under mild conditions, copper-catalyzed isonitrile and allene are subjected to a cyclization reaction, and a simple polysubstituted pyrrole synthesis method is opened up. The compound is shown as the following general molecular formula, wherein R1 and R2 are alkyl groups or aryl groups for providing electrons, and R3 is an alkyl group or halogen. The method is used for synthesizing a series of three-bit aryl sulfone functional group containing 2,3,4-tri-substituted pyrrole compounds for the first time, and the method has wide prospects on the aspect of synthesis and application of a built compound library. Two of the synthesized three-bit aryl sulfone functional group containing 2,3,4-tri-substituted pyrrole compounds are selected for testing in-vitro tumor cell inhibitory activity, and the compound has inhibitory activity on human leukemia cells (HL-60). The formula is shown in the description.