Effective grooving construction method for underground continuous wall in slightly-weathered limestone with overlying sandy soil

The invention provides an effective grooving construction method for an underground continuous wall in slightly-weathered limestone with overlying sandy soil. The method specifically comprises the steps of 1) performing core drilling in a grooving area to determine rock characters; 2) measuring the position of a setting-out calibration guide wall; 3) performing guide wall construction and determining the distribution of hole punching positions; 4) drilling guide holes, and installing guide rods; 5) punching a rock layer by using a heavy hammer and grabbing crushed rocks by using a grooving machine; 6) brushing a wall by using a square hammer and connecting the holes to form a groove; 7) cleaning the bottom of the groove to finish the grooving construction. The construction method provided by the invention has the advantages that the defects and the shortages of unsafe and unstable factors, slow construction progress, poor grooving quality and the like are overcome, and the effective, low-cost and high-accuracy grooving construction in the slightly-weathered limestone is realized; the construction effect is good, the grooving speed is fast, the construction process is simple and convenient and the construction period is greatly shortened.