Abstract: It is significant for the ecological and environmental protection to explore low−cost adsorbents for the efficient removal of heavy metal ions from industrial wastewater. In this work, fluorite tailings were used as raw material and treated through alkaline fusion at 600 ℃ for 3 hours to extract silicon component . Subsequently, the extracted silicon component was converted into mesoporous molecular sieve (MCM−41) via a low−temperature crystallization method. Particularly, cetyltrimethylammonium bromide (CTAB) was used as a template agent during the preparation process of MCM−41. Then, calcium silicate hydrate (CSH) adsorbents were prepared using MCM−41 as template and silicon source. A series of characterization methods including XRD, FT−IR, SEM, XPS and TEM were carried out to analyze the microstructure of the CSH adsorbents before and after the adsorption of Ni²⁺. The influencing factors of hydrothermal time, adsorption reaction temperature, contact time, and pH value on the adsorption performance of CSH for Ni²⁺ were systematically investigated, and the isotherm model, adsorption kinetics and adsorption thermodynamics of the adsorption process were analyzed. The results show that highly dispersed CSH with a thickness of only 3.8 nm can be obtained at the hydrothermal time of 12 h, and the elements of O, Si and Ca are uniformly distributed within CSH. The removal rate of Ni²⁺ by CSH is 97.7% at an initial mass concentration of 250 mg/L within 8 h, and the maximum adsorption capacity can reach 496.72 mg/g. Moreover, the adsorption performance increases significantly with the increase of reaction temperature and solution pH value within a certain range. The adsorption of Ni²⁺ by CSH is dominated by electrostatic attraction and ion exchange, and the adsorption process belongs to monolayer adsorption. The present work provides a cost−effective route for the utilization of fluorite tailings to prepare highly efficient CSH adsorbent towards Ni²⁺ purification in industrial wastewater.