The invention provides a small tea bag with a self-sealing function. A small self-sealing zipper is arranged at a bag opening of a tea bag body; and when a user opens the tea bag body, tea needed by the user is poured out, then the small zipper is zipped up, thus, the rest of the tea makes no contact with the air and is prevented from being affected with damp, and the small tea bag is quite convenient to carry and use.