The invention belongs to the technical field of underground grouting reinforcement and support of coal mines and relates to a method for reinforcing and supporting a roadway under the condition of high ground stress of a kilometer deep mine. The method includes the steps of mounting of grouting anchor cables, grouting construction and tensioning of the anchor cables. The method has the advantagesthat the method is simple and reinforces initial fissures in roadway surrounding rocks and fractures caused by excavation disturbance by grouting, so that the engineering mechanics performance of theroadway surrounding rocks is improved; the grouting slurry diffusion radius can be increased through splitting grouting, making soft rock with relatively softened strength of deep surrounding rock issolidified into a concrete structure with higher strength, and a closed strong bearing structure is formed by the concrete structure with shallow surrounding rock, so that the self-bearing capacity ofthe surrounding rock and the supporting capacity of a supporting system are given to full play; meanwhile, grouting also provides a stable bearing layer for the combined anchor cables, and the radialpressure provided by tensioning the combined anchor cables can change the stress state of the surrounding rock and increase the stable creep value of the surrounding rock so as to ensure long-term stability of the surrounding rock of the roadway.