Provided are a heterocyclic carboxylic acid amide ligand and applications thereof in a copper catalyzed coupling reaction. Specifically, provided are uses of a compound represented by formula (I), definitions of radical groups being described in the specifications. The compound represented by formula (I) can be used as the ligand in the copper catalyzed coupling reaction of the aryl halogeno substitute, and is used or catalyzing the coupling reaction for forming the aryl halogeno substitute having C—N, C—O, C—S and other bonds.