Abstract: Based on engineering practice and amounts of geological survey analysis, combined with the theory of engineering geology and the principle of large deformation mechanics, the compound deformation mechanics mechanism of soft rock with tiny swelling and structure-deformed type (JS) was affirmed in the roof of coal roadways in Zhenchengdi Coal Mine, China. FLAC was used to analyze the mechanical measures and optimize support parameters while the deformation mechanical mechanism of soft rock transforming from compound to simple. The results of field experiments showed that the compound supporting of bolt-wire mesh-anchor has successfully solved many difficult problems for years in coal roadways of Zhenchengdi Coal Mine.