Abstract: In order to understand the thickness of each layer of the composite roof and to determine the position of hard delamination in the case of only obtaining the monitoring data of roof delamination, a method for inversion of each layer thickness of composite roof was proposed based on the support failure section of N3702 transport lane of the Yuyang coal mine. In light of the monitoring data of roof delamination, the position of delamination void and the amount of delamination were analyzed; the composite roof was simplified as a simply supported beam and its deflection equation was deduced, and the first stratified mudstone layer was inverted combined with the maximum roof subsidence; the remaining delamination thicknesses were reasonably assumed, and each delamination thickness was inversed by combining compound stratification and the actual roof delamination. The field test results show that the hard stratified position determined by each stratification thickness of composite roof inversed by the proposed method can effectively optimize the parameters of roadway support, and the roof subsidence of test section is reduced by 127mm and continuous roof deformation is shortened by nearly 25 days compared with that of original support.