Employing the Pechmann method, with the acid catalyst, 7-hydroxy-4-methyl coumarin fluorescent whitening agent was synthesized by resorcinol and ethyl acetoacetate, through the dehydration condensation reaction. Then, the hindered amine light stabilizer 4-amion-2,2,6,6-tetramentylniperidine, coumarin type fluorescent brighteners and taurine were putted into the same molecular, with cyanuric chloride as crosslinking molecular, a new kind of yellowing inhibitor was synthesized. Using infrared spectrum characterized the structure of yellowing inhibitor, then, ultraviolet spectrum and fluorescence spectrum were employed to discuss its yellowing inhibition mechanism, and then, the application effect of the yellowing inhibitor was investigated through the Uv accelerated aging test. The results show that the yellowing inhibition effect of the new kind of yellowing inhibitor was better than the 7-hydroxy-4-methyl coumarin and 4-amion-2,2,6,6-tetramentylniperidine.