The preparation of zeolite F from coal fly ash is highly desired. F-typed zeolite was prepared by acidic pretreatment-alkali fusion activation-hydrothermal crystallization with circulating fluidized bed fly ash as raw material and used for adsorption of methylene blue. The influence of acid leaching temperature, alkali melting temperature and mass ratio of alkali to ash on the structure of fly ash, as well as the influence of alkali melting temperature, mass ratio of alkali to ash, volume to mass ratio of liquid and solid and crystallization time on the structure and morphology of zeolite were investigated. The crystal structure and morphology of zeolite were characterized by XRD and SEM, respectively. The results show that the optimum conditions for preparing highly purity F-type zeolite with fly ash in circulating fluidized bed are as followed: alkaline fusion temperature of 550 ℃, alkali to ash ratio of 1.5∶1, liquid to solid ratio of 12 mL/g, amount of crystal directing agent up to 10%, crystallization temperature of 100 ℃, crystallization time of 20 h. And its specific surface area was up to 357 m2/g, and the saturated adsorption capacity of methylene blue amounted to 178 mg/g.