Over-grouting length control device for cast-in-situ bored pile

The utility model discloses a cast-in-situ bored pile over-grouting length control device which comprises a closed buoyancy tank, the closed buoyancy tank is in a hollow cube shape, a balancing weight is vertically welded and fixed to the middle of the upper portion of the closed buoyancy tank, and the upper portion of the balancing weight passes through a vertically-welded connecting steel bar. One group of first connecting sleeves are arranged at one end of the upper part of each first connecting sleeve, the first connecting sleeves are vertically welded and fixed right above the first connecting sleeves, movable adjusting steel bars are vertically reserved in grooves reserved above the first connecting sleeves, the adjusting steel bars are extruded and fixed by bolt knobs reserved on the outer walls of the first connecting sleeves, and the other group of first connecting sleeves are reserved at the other ends above the adjusting steel bars; and the other group of connecting steel bars are vertically welded