The invention relates to a method for preparing analcite through high-alumina fly ash. The method includes the following steps of firstly, conducting a pre-desiliconization reaction through a sodium hydroxide solution and high-alumina fly ash, and obtaining a solid phase desiliconization fly ash and a liquid phase desiliconization alkali liquid after filtering and washing a reaction solution; secondly, adding desiliconization fly ash obtained in the first step to serous fluid prepared from sodium carbonate and limestone to obtain mixed serous fluid, and obtaining a sodium aluminate solution through sintering and clinker dissolving-out procedures; thirdly, conducting purification and impurity removal on desiliconization alkali liquid obtained in the first step, and mixing and homogenizing alkali liquid and the sodium aluminate solution obtained in the second step, and obtaining analcite through the crystallization reaction, filtering, washing and drying. In the scheme, the solid phase is dried to obtain analcite, and the liquid phase is evaporated and concentrated to return to the pre-desiliconization procedure to the reused. The method has the advantages of being simple in process, low in energy consumption, low in cost, high in raw material utilization rate, high in purity, small in granularity, uniform in granularity, suitable for industrial popularization and the like.