The invention relates to an anti-floating airtight stopper. A deformable material is mainly used for making a stopper body provided with a first air chamber and a second air chamber which are adjacent but not communicated, and the first air chamber and the second air chamber are respectively provided with an opening. The stopper body is combined to an opening of a container, the second air chamber is communicated with the interior of the container, and the first air chamber is not communicated with the interior of the container; and moreover, a sealing body can be utilized to cover the opening of the first air chamber.