The invention discloses a carboxamide compound, a preparation method and an application thereof as a stable and efficient anti-oxidation stabilizer, and belongs to the technical fields of novel anti-oxidation stabilizer compounds and preparation thereof. The compound has a stable carboxamide bond and is connected to form anti-oxidation stabilizers having different stabilizing structures, and the nvalue is adjusted to generate fat chain products having different lengths to make the products well matched with a specific polymeric material in performances, so the problems of fast volatilizationand easy extraction of a micro-molecular stabilizer in the polymeric material are solved, the service life of the material is greatly prolonged, and the compound has a strong and lasting polymeric material protection performance. Compared with antioxidants in the prior art, the above stable polymeric antioxidant has the advantages of strong resistance to hydrolysis, acidolysis, alkaline hydrolysisand chemical pollution environment degradation, and provides a good antioxidant choice for the development of modern new materials. The carboxamide compound has the characteristics of non-volatility,good matching performance with the polymeric material, strong polymer protection capability, good environmental protection performance, beauty, durability and low cost.