Rooday driving along goaf was one of the most effective way to reduce coal pillar concealed coal and improve mining recovery rate, and was widely used in relatively simple hydrogeological conditions of mining area. With analog simulation means, reasonable size of small coal pillar in 4201 working face along the empty roadway of Kouqian Mine, Lanhua Group was 4 m, through the industrial mineral pressure observation on site, the deformation law of surrounding rock along the empty roadway was analyzed, which provided experiment  basis for practice on site.