A karst cave grouting reinforcement structure at least comprises grout jacking rubber tubes, a dial indicator, a displacement transfer bar, a steel plate clamp, a concrete roof, pebbles, a mud hemp bag and grout jacking tubes. The displacement transfer bar is located in the middle of the whole structure; the dial indicator is arranged at the upper end of the displacement transfer bar and located on the outer surface of the displacement transfer bar in a sleeving mode; the grout jacking tubes are symmetrically arranged on the two sides of the displacement transfer bar and placed vertically; the grout jacking rubber tubes are arranged at the top ends of the grout jacking tubes and connected with the grout jacking tubes; the concrete roof is arranged under the displacement transfer bar and placed horizontally; the steel plate clamp is tightly embedded into the upper surface of the concrete roof; the pebbles are evenly and symmetrically arranged on the two sides of the grout jacking tubes; the mud hemp bag is arranged between the pebbles and wraps the lower ends of the grout jacking tubes. The karst cave grouting reinforcement structure can achieve effective sand reinforcement and water shutoff and is safe and stable, so that the stratum is solidified, a good grouting reinforcement effect is achieved, and the karst cave grouting reinforcement structure is suitable for application and popularization.