The sepiolite chelating agent is processed and prepared from modified sepiolite, biomass material, redox agent and other materials, and achieves arsenic, cadmium, lead, etc. through a series of physical and chemical reactions such as adsorption, chelation and redox. Stabilization of heavy metals, which in turn reduces their mobility and bioavailability. The sepiolite chelating agent has passed the authoritative appraisal and has been appraised by the Chinese Academy of Environmental Sciences (Zhongke Kejianzi [2018] No. 62). The expert group has consistently assessed that the product has reached the domestic leading level. The modified sepiolite has large surface energy and chemical activity, has strong adsorption performance and ion exchange capacity, and has characteristic adsorption and stabilization effects on heavy metals. Based on the special properties of modified sepiolite and other functional additives, heavy metals such as arsenic, cadmium and lead are fixed by characteristic adsorption, redox and chelation. At the same time, the heavy metal is further sealed in the curing net by lattice sealing, thereby realizing the stabilization of heavy metal solidification. After being repaired by sepiolite chelating agent, the leaching concentration of heavy metals such as arsenic, cadmium and lead in the soil reached relevant control requirements. At present, thousands of tons of sepiolite chelating agent have been applied successfully to many heavy metal contaminated soil remediation projects such as remediation of contaminated land in the West Plant of Hunan Nantian Chemical Plant. Sepiolite chelating agent have been highly evaluated by cooperative organizations such as BCEG Environmental Remediation Co., Ltd.