Abstract: The deformation characteristics of coal roadway with broken roof, its failure mechanism and its controlling countermeasures are systematically researched through field investigation, theoretical analysis and numerical testing . Research shows that the former support pattern is unable to enhance the stiffness of the lower strata of broken roof .It results protecting effect in support system was exploited and support system was destroyed one by one. Finally, the roadway loses stability. The blocks structure of roadway roof mechanical model is established and analysis shows that supporting by bolt and anchor can not satisfy the demands of supporting . The combined support “bolt/steel mesh/anchor plus grouting blot” was putting forward to enhance the of cohesion of construction surface and improve the mechanical characteristics of the broken surrounding rock which lead to support system would not fail.The engineering application presents that it can solve the large deformation of large secton coal roadway with broken roof which can provide reference for roadway support in similar geology strata.

Key words: Mining Engineering, broken roof, bolting, surrounding rock Control