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采用盆栽试验模拟土壤镉(Cd)污染，通过施用不同浓度硅(Si)，研究其对Cd污染土壤中Cd活性以及小麦生长和Cd吸收累积的影响。结果表明：在模拟Cd污染土壤上，Si施入降低了土壤Cd的有效性，表现为其显著降低了土壤交换态Cd比重，但显著增加了结合态和残渣态Cd比重(P＜0.05)；0.5 g/kg及以下Si用量显著抑制了小麦对Cd的吸收且促进了Cd向地上部分的运输(P＜0.05)，其中以0.5 g/kg效果最好，该处理下小麦地上部分和总Cd积累量分别比无Si处理(Cd1.5Si0)降低34.09%和50.40%，而转移系数达到了1.44；此外，Si浓度小于0.5 g/kg时缓解了Cd污染对小麦生长的抑制作用，其中以0.5 g/kg用量最好，其总干重提高了20.32%，但Si水平超过1.0 g/kg时抑制了小麦幼苗的生长。综合而言，0.5 g/kg Si能抑制土壤Cd活性，降低小麦对Cd的吸收累积，有效缓解土壤Cd污染对小麦生长的抑制作用，是较适宜的施用量。“,”A pot experiment was conducted to simulate soil Cd pollution and investigate the influence of different levels of exogenous silicon on the activity of Cd in soil, wheat growth and Cd uptake by wheat. The results showed that the exogenous silicon decreased the activity of Cd in soil, which significantly decreased the proportion of exchangeable Cd, but significantly increased the proportion of bound and residual Cd (P<0.05). Silicon content ≤ 0.5 g/kg could inhibit the uptake of Cd by wheat obviously and promote the Cd transport to the overground part, and 0.5 g/kg silicon content had the best effect, in which, the Cd accumulation in the overground part and total plant decreased by 34.09% and 50.40% compared with non-Si treatment (Cd1.5Si0), and the transfer coefficient reached 1.44. Si content under 0.5 g/kg alleviated the inhibition of Cd contamination on wheat growth, and 0.5 g/kg had the best effect, in which the total dry weight of wheat increased by 20.32%, but Si content＞1.0 g/kg inhibited wheat growth. In conclusion, 0.5 g/kg Si could inhibit the activity of soil Cd, reduce the Cd uptake by wheat and alleviate the toxic effect of Cd on wheat growth, which was the optimum application amount.