Abstract: Argillaceous soft rock roadway in Kailuan presents full-face nonlinear large deformation characteristics. SEM, TEM, and X-ray diffraction are all applied in the mechanism research. As a result of the experiments, softening and expansion mechanism in argillaceous strata roadway with high content of montmorillonite is obtained. Implementing backfilling, lag grouting technology to leg-lock support which has critical points. The combined support is effective to control the deformation.