Abstract: In view of the problems such as spray layer falling off, decrease of anchoring force and serious floor heave which appear in the western weakly cemented soft rock roadway, we carry out field sampling in main transport roadway sandy mudstone formation of Inner Mongolia Luxin Mining Area and triaxial tests have been performed in different confining pressure. The experiment date show that the stain behavior has the obvious softening characteristic after peak strength, and there is residual deformation stage. So it is more suitable for thilinear strain softening model to analyze. By means of FLAC double linear strain softening model to carry out fish correction and to realize the numerical application of the model. The verification model shows that the thilinear strain softening model even more conforms to the deformation characteristics of mudstone. Through the analysis of construction stability of mudstone roadway and the evaluation with the help of softening degree index. It shows that the mudstone roadway under the effect of the anchoring and shotcreting support has little influence on controlling the deformation of surrounding rock because of the maximum degree of softening and the increasing of softening depth. And the bolt axial force increases and later decreases and loses support ability in the end.