Abstract: Bifurcation often occurs in thick coal seams，the thickness of the band between the upper and lower layers usually varies greatly.When the band thickness is small，the band and the lower coal seam are affected by the mining of the upper coal seam and will be damaged，which brings great difficulties to the support of the lower mining roadway.Taking the No.9 mining area of one coal mine as engineering background，with site measurement and theory analysis，rigidification theory of roof slab with thin band was established.The feasibility of rigidification and the stability of strata after rigidity were analyzed，and the classification of the stability of the top-bed refuse in the mining roadway with thin section of goaf under goaf was formed.Three types of roadway roof were divided into three categories：band layer thickness greater than 5 m，3～5 m and less than 3 m，and three types of support schemes were proposed.