The invention discloses a method for synthesizing an alpha,beta-unsaturated amide compound through visible light catalysis, and belongs to the technical field of organic synthesis. The method comprises the following synthesis steps: subjecting a phenylethylene compound and a formamide compound to a reaction under the conditions of a nitrogen atmosphere and a temperature and under the actions of visible light radiation and synergistic effects of an oxidant and a photocatalyst, and carrying out extracting, drying, concentrating and purifying so as to obtain the alpha,beta-unsaturated amide compound. The method provided by the invention has the advantages of simple and easily-available raw materials, stable chemical properties, mild reaction conditions, simple operation, strong substrate applicability and the like, can be widely applied to drug synthesis and organic molecule synthesis, and has wide industrial application prospects.