The invention relates to an arc-shaped GRG mounting structure which comprises a first mounting assembly and a second mounting assembly. The first mounting assembly is connected with the second mounting assembly, the first mounting assembly comprises a connecting piece and a control piece, the connecting piece is connected with the control piece, and a bearing is arranged on the control piece. The second mounting assembly comprises a support, sliding rails are arranged on the support, the control piece is connected with the sliding rail through the bearing, and the control piece can rotate and slide relative to the support. According to the arc-shaped GRG mounting structure, two arc-shaped GRG units are adjustably spliced; then, the front-back and vertical space adjustment of arc-shaped GRG is achieved through control of basic-layer anchoring parts and the rails, and basic layer maintenance on the arc-shaped GRG and line maintenance on lamp light control can be achieved; meanwhile, the mounting efficiency of the arc-shaped GRG is improved, the loss of manpower is lowered, and the construction period can be shortened.