The invention discloses a method for stabilizing phosphite ligand and an application thereof. Cyclodextrin compounds are added into a reaction system under the existence of phosphite ligand, so as torestrain degradation of ligand. In the reaction system, phosphite ligand is served as a catalyst of reaction or phosphite ligand and transition metal are jointly served as the catalyst of reaction. According to the method, the decomposition of phosphite ligand in the reaction system can be effectively restrained, the service life of phosphite ligand can be prolonged and the purpose of increasing reaction efficiency can be achieved.