The work aims to prepare polyvinyl alcohol (PVA)/montmorillonite (MMT)/potassium sorbate active packaging film and investigate the film properties and the release effect of potassium sorbate in the film. The PVA/potassium sorbate films with different contents of MMT were prepared by casting method. The color, opacity, tensile strength and water content of active packaging films were analyzed. The release behavior of potassium sorbate to fatty food simulant in the films was also studied. The properties of the films were improved by MMT. The addition of MMT resulted in a significant increase in tensile strength, a decrease in theelongation at break as well as the deepening of the color and the reduction of transparency of PVA films. The water content of PVA films was decreased with the increase of MMT content. The addition of MMT could significantly change the release behavior of potassium sorbate to fatty food simulant. When MMT content was 2%, the release of potassium sorbate was reduced obviously. The color, tensile strength, water content and release behavior of potassium sorbate of the films can be changed by adjustment of MMT content.It is reliable to fit the release of potassium sorbate by Fickian second law, which provides reference for the further development of potassium sorbate antibacterial packaging materials.