Rotary drilling process in pile foundation construction

The invention discloses a rotary drilling process in pile foundation construction, which is used for underwater drilling and comprises the following steps of: assembling a corresponding drilling barrel according to a drilling torque, and specifically, adjusting the length of the drilling barrel and the inner diameter of the drilling barrel to correspond to the drilling torque; obliquely-arranged or vertically-arranged hobs are assembled along the bottom of the drill barrel with the group as the unit, so that hob faces are formed; the upper part of the drill cylinder is connected with a drill rod through a drill rod connecting sleeve; a flow guide assembly is assembled on the outer side of the drill barrel with the position above the hob as the starting position; the drill rod is started, while the drill rod rotates, the hob drills the core column along the wall of the drill barrel, water on the outer side of the drill barrel moves from bottom to top along the flow guide assembly and forms a vortex at the top,