In this study, millimeter scale magnetic particle materials were prepared by using thiol-functionalized MgAl-LDHs from four different sources, respectively, their impacts of dosage and treatment time on the effect of Cd removal were examined, and then the removal effect and mechanism of MgAl-LDHs-C on the removal of Cd in three actual contaminated agricultural soils (total Cd 0.73-0.86 mg/kg) were investigated. The results showed that MgAl-LDHs-C magnetic particle made from Tech-layer MgAl-LDHs had the best removal effect. The optimum mass ratio of MgAl-LDHs-C to soil was determined to be 1:10, and the optimal reaction time was 3 h. Under this condition, the DTPA extracted Cd content in soil from Taizhou City of Zhejiang Province decreased from 0.56 mg/kg to 0.30 mg/kg. Under optimum conditions of liquid-solid ratio 2:1, reaction temperature 25℃, oscillation frequency 180 r/min, the total Cd removal rates of the soils collected from Taicang City of Jiangsu Province, Baiyin City of Gansu Province and Taizhou City of Zhejiang Province were 26.0%, 23.8% and 34.7%, respectively. In conclusion, MgAl-LDHs-C addition can significantly lower soil acid-soluble, reduced and oxidized Cd contents, and the MgAl-LDHs-C material prepared in this study demonstrates strong soil Cd removal ability, which can provide a scientific basis for the reduction remediation of Cd-contaminated farmland soil.