Abstract: In order to solve large deformation,serious floor heave,ifficult support and other problems of Tertiary soft rock roadway in Liuhai Mine,with comprehensive application of site engineering geological survey,physicochemical analysis,method analysis numerical simulation,engineering experience analysis and other method,a deep study was conducted on deformation failure mechanism and support measures of mine roadway. The study results showed that deformation mechanics mechanism of Tertia ry complex type soft rock in the region was molecular water absorbent,crack swelling type + structure stress,gravity,engineering deviatoric stress dilatancy type + random j oint type,such as Type I ACI ABDIE. According to the type of complex deformation mechanics mechanism,application of " bolt 1 steel mesh /anchor + floor bolt + flexible layer truss" support measure was provided. The complex type deformation mechanics mechanism was converted to single type deformation mechanics mechanism and the numerical simulation method was applied to study on the plan principle and feasibility. The engineering application showed that the above support measures solved large d eformation engineering problem of soft rock roadway in Liuhai Mine and would have certain references and promotion value to engineering project with similar geological C ondition.