Abstract: Fly ash is a main solid waste produced by coal combustion. The large number of accumulation hazards are serious. The extraction of alumina from fly ash can solve the shortage of aluminum fly ash and the accumulation of fly ash in China at the same time. In this paper, some popular processes of extracting alumina from fly ash are reviewed from three general directions: acid method, alkali method and acid-base combination method. The advantages and disadvantages of various methods were analyzed. The prospect of extracting alumina from fly ash was prospected.