The invention relates to an adsorbent used for decreasing heavy metal ion content in tobacco extraction liquids and an application of the adsorbent. Tobacco stalks of tobacco stems are used as raw materials to prepare the adsorbent; a specific surface area increasing process, a soaking process by using a mixed solvent consisting of a low molecule alcohol and chloroform, and solid-liquid separation are performed orderly to obtain the adsorbent. The adsorbent used for decreasing heavy metal ion content in tobacco extraction liquids provided by the invention uses the tobacco stalks as raw materials, a specific surface area increasing process is performed, and then a modification treatment by using the mixed solvent consisting of the low molecule alcohol and the chloroform is performed to obtain the adsorbent. The tobacco stalks have a same source with tobacco leaves, have basically same compositions with the tobacco leaves, and thus do not bring non-tobacco components into tobacco extraction liquids. In addition, each tobacco stalk itself has a large amount of potential adsorption sites for metal ions, can create conditions for the adsorption of heavy metal ions through modification treatment, and an adsorption experiment proves that the adsorbent shows good adsorption effects of heavy metal ions in tobacco extraction liquids.