Abstract: For the problems of composite roof, low strength of two-side and difficult control of the large deformation by traditional shed support in mining roadway of a southwest coal mine, using numerical simulation method, the paper analyze the stability mechanism of roadway surrounding rock with composite roof, the damage of two sides and shallow roof and deep surrounding rock of coal roadway with composite roof is in the form of tension shear damage and failure form of shallow roof is mainly tensile failure, and the function of the bolts can significantly reduce the tension shear failure of deep surrounding rock and two sides and shallow roof, enhance the stability of roadway. Combined with the actual geological survey of the working face, the support parameters of the roadway are determined. The results of the experiments show that the proposed parameters can effectively restrain the deformation of the surrounding rock, and verify the rationality and reliability of the research results.