Abstract: With the expansion of the application range and usage of aluminum-air batteries, the recycling of electrolytes has become an urgent issue in this field. In this paper, aluminum-air battery waste electrolyte is used as raw material, and the high-purity ultrafine alumina is prepared by seed crystal controlled precipitation method and unconventional metallurgy. The main research is to remove high-purity alumina from the sodium aluminate solution containing various impurities by impurity removal, seed decomposition, acid solution, precipitation, drying, calcination, grinding and dispersion, and carry out a series of characterization and analysis of the product, it is proved that the high-purity alumina with a purity of 99.99% or more can be obtained by using the waste electrolyte of the aluminum-air battery as a raw material.