The invention discloses a preparation method of a sepiolite adsorbent. The preparation method of the sepiolite adsorbent comprises the following steps: acidizing sepiolite, then washing the sepiolite with water until the sepiolite is neutral, and drying the sepiolite to obtain preprotreated sepiolite; adding an organic solution into the preprotreated sepiolite, steeping the preprotreated sepiolite, performing filtration, water washing, drying and grinding after steeping is finished, then introducing nitrogen, and performing activation at a temperature of 300-600 DEG C, thereby obtaining modified sepiolite; mixing the modified sepiolite with semi coke in proportion, thereby obtaining the sepiolite adsorbent. The sepiolite adsorbent prepared by the preparation method of the sepiolite adsorbent, provided by the invention, has the characteristics of good adsorption property and low cost; a regeneration method of the adsorbent is simple and low in regeneration energy consumption; based on the preparation method of the sepiolite adsorbent, the invention also provides the sepiolite adsorbent and the regeneration method of the sepiolite adsorbent.