Abstract:The bored-grouting pile with diameter of 1000~2000 mm and depth of 100~130 m are often used in various projects. Pump-suction reverse circulation was traditionally used in the hole not more than 80 m deep, but by the improvement on the existing reverse circulation drill, the efficiency of pump-suction reverse circulation was greatly improved with pile hole of 18 m in diameter and 131 m in depth finished.