A dried food fresh-keeping packaging bag structure is provided. When the user wants to pack a dried food, a pull portion of a fresh-keeping exhaust valve is pulled outwardly toward the outside of the mouth of the packaging bag to tear a first sealing film to open a filling chamber. Then, the dried food is placed into the packaging bag, and the mouth of the packaging bag is closed. The exhaust valve blocks the outside air from returning to the interior of the packaging bag to provide a non-return exhaust effect. A preservative in the filling chamber communicates with the interior of the packaging bag to dehumidify or deoxidize the air remaining in the packaging bag.