Abstract: Aiming at the problems that large resources are left in the mine and large amount of coal gangue is hoisted and piled on the surface, the paper put forward unequal strength complete filling mining technology for roadway. Roof stability and its instability destruction mechanism were analyzed. The conditions of roof deflection increase, the occurrence of non-controlling displacement are calculated. The displacement of the overlying strata and stress-transferring rule are analyzed after strip mining and pillar recovery with numerical calculation software. Research shows that strata behaviors are not obvious, main roof is not ruptured, and the surface deformation is within the fist degree damage.