System for preventing sediment at bottom of pile after large-diameter rotary drilling, pouring and hole cleaning

The utility model discloses a pile bottom sediment prevention system after large-diameter rotary drilling hole pouring and hole cleaning, which comprises a large-diameter rotary drilling hole, an isolation layer, a mud pit and a grouting guide pipe, the mud pit is provided with a mud isolation area and an air lift reverse circulation hole cleaning separation area, the isolation layer is positioned at the bottom of the large-diameter rotary drilling hole, and the gas lift reverse circulation hole cleaning separation area is positioned at the bottom of the large-diameter rotary drilling hole. One end of the grouting guide pipe is inserted into the isolation slurry area, the other end of the grouting guide pipe is inserted into the isolation layer, the grouting guide pipe is provided with a booster pump, and a guide pipe limiting device is installed at the top of the large-diameter rotary drilling hole and comprises a limiting installation plate horizontally installed at the top of the large-diameter rotary dril