According to the support problem of deep roadway surrounding rock deformation in Qujiang Mine, theoretical analysis, numerical simulation, laboratory experiments and field investigation was applied to analyze the deformation mechanism and best time of secondary cable support. The results show that the major reason cased the large deformation of surrounding rock with high stress is the surrounding rock creep and unreasonable support form, roof and base angle anchor cable can greatly improve the stress state of surrounding rock, especially on reducing the stress transfer from the two sides to the floor. The best time of secondary cable support is one month later after the roadway have been excavated and bolt-mesh-supported.