The invention discloses a rechargeable aluminum ion cell and a preparation method thereof and belongs to the field of energy reutilization. The cell comprises an anode, a cathode, a liquefied aluminum ion electrolyte and a diaphragm material, wherein the anode is made of graphite structure carbon material; the cathode is made of highly pure aluminum; the liquefied aluminum ion electrolyte is formed by mixing anhydrous aluminum chloride and 3-methyl imidazole compound; the molar ratio between the anhydrous aluminum chloride and the 3-methyl imidazole compound is from 1.1:1 to 1.6:1. The preparation process of the cell comprises the following steps: processing the graphite structure carbon material into laminar shapes; fixing the anode material with inertial metal foil as a current collector and covering the anode with the diaphragm material; washing highly pure aluminum cutting piece as the cathode; preparing the liquefied aluminum ion electrolyte which contains A13 plus ion capable of freely moving. The anode, the cathode and the liquefied aluminum ion electrolyte are assembled in a glove box to form the cell; the cell has the characteristics of high capacity and good circulating stability and is applicable to multiple fields such as electronic industry, communication industry and electric automobile.