The utility model discloses a sealing structure, include mouthful frame (1) and be used for the lid to close flap (2) on the mouth frame (1) both ends that flap (2) and mouthful frame (1) lid closed be equipped with a pair of each other for the composite seal pad of joint, the composite seal pad is including sealed pad (3) of two reverse dislocation set on flap (2) bottom and mouthful frame (1) upper portion. The utility model discloses simple structure, sealed effectual, life is longer, and the installation is more convenient with the change.