Abstract: For the control problem in large deformation of mining roadway with 20 m width coal pillar in Wangjialing Coal Mine, the distribution and migration of the second invariant deviatoric stress of roof rock and coal was researched by numerical simulation. The research results show that the optimal pillar width is 4 m to 8 m between adjacent caving mining sections in 203 panel, and the asymmetric support technique is needed to carry out reinforced support. The 8 m pillar was tested first in field, and the parallel-arranged asymmetric support technology composed of channel steel truss cable and single cable was applied at 20321 fully mechanized caving face return roadway. The maximum roof subsidence is 102 mm, and the design width of coal pillar is reasonable.