The invention discloses a method for recycling an electrolyte of an aluminum-air battery. The method comprises the steps of: diluting a failed electrolyte, performing cooling, standing and layering, collecting a lower-layer precipitate, adding one or more than one seed crystals into the lower-layer precipitate for crystallization to promote most of dissolved aluminum to precipitate, performing centrifuging, drying, firing to obtain alumina, and electrolyzing the alumina to obtain pure aluminum, wherein the separated supernatant can be added with an electrolyte for repeated use. The invention also discloses an aluminum-air battery with the novel electrolyte prepared by the method. Compared with the prior art, the method can effectively remove the aluminum hydroxide precipitate and most of dissolved aluminum in the electrolyte, and does not introduce impurity phases, so that the centrifuged solution can be used as the electrolyte again after the electrolyte is added, and the resource utilization rate is improved. The method is safe, effective, easy to operate, capable of being performed in a fully-closed environment, capable of purifying the working environment, capable of effectively avoiding environmental pollution, low in requirement on equipment and suitable for large-scale industrialization.