Effect of activation temperature, pH value, co existing anion and ionic strength on fluoride adsorption by the thermally dehydrated aluminate cement granules(ALC) were investigated, and TGA, XRD, FTIR, SEM were used to analyze their surface morphology, internal structure characteristics and adsorption mechanisms. The results show that the equilibrium adsorption capacity of ALC is higher than 1742mg/g at 25℃, the activation temperature of ALC is 600℃(ALC600), pH=7, and the initial fluoride concentration is 100mg/L. ALC600 can efficiently remove fluoride from water in a wide pH range of 59. Co existing anion(Cl-，NO-3 and SO2-4) and ionic strength do not evidently inhibit fluoride removing by ALC600. The adsorption processes can be fitted as pseudo second order model and Langmuir model, and maximum adsorption capacity is over 22372mg/g. According to the change of crystal structure, chemical bond and surface morphology of ALC600, the process of fluoride removed by ALC600 is mainly due to chemical adsorption, internal complexion and surface precipitation, the ion exchange and electrostatic interaction are also involved.