在厚冲积层条件下，冲积层和基岩作为两种不同的介质，其岩性和结构各不相同，在建立采动沉陷模型时，应当把它们作为两种不同的介质处理，合理地考虑冲积层和基岩对地表移动的综合影响。本文分别对冲积层和基层的移动特征作了理论上的探讨，并利用力学理论建立了复合岩层采动沉陷预计模型。 Under thick alluvium, alluvium and bedrock are two different media, and their lithology and structure are different. When mining and subsidence models are established, they should be treated as two different media, and reasonable consideration should be given to The combined effect of alluvium and bedrock on surface movement. In this paper, the movement characteristics of alluvium and grassroots are theoretically discussed respectively, and the prediction model of mining subsidence of composite rock is established by mechanics theory.