Externally-attached bottle plug of volumetric flask

The utility model relates to the technical field of volumetric flasks, in particular to an externally-attached bottle plug of a volumetric flask. In order to solve the problem that a bottle plug is difficult to rotate and open due to the fact that a cover is tightly adsorbed on a bottle opening possibly caused by the pressure difference between the inside and the outside of a volumetric flask container, the following technical scheme is provided: the bottle comprises a bottle body, and the bottle body comprises a bottle body and a bottle neck; the connecting structure is mounted at the top of the bottle neck, and the connecting structure can be detached and then taken down; the sealing assembly is used for sealing the bottle body, so that the sealing performance and the stability of liquid in the bottle body are ensured; and the connecting belt is connected between the connecting structure and the sealing assembly, so that the connecting structure is prevented from being separated from the sealing assembly. A