The invention relates to a cast-in-situ bored
pile grouting device and a construction method thereof. The cast-in-situ bored
pile grouting device comprises a rack arranged at an orifice of a foundation
pile, two sliding seats symmetrically sliding in the radial direction of the orifice on the rack, guide rollers rotationally arranged on the side walls, close to the orifice, of the sliding seats, and a driving device for driving the two sliding seats to synchronously and reversely slide are arranged on the rack; the cast-in-situ bored pile grouting device further comprises lap-joint lugs whichare fixedly connected to the outer walls of the two ends of a
pipe section, a lap-joint table is arranged on the sliding seats in a lifting mode in the vertical direction, and a lifting device used for driving the lap-joint table to ascend and descend in a reciprocating mode is arranged on the sliding seats; and when concrete is poured, the spliced
pipe section is inserted into the orifice, the two sliding seats are driven to synchronously get close to each other and clamp a grouting
pipe, the guide rollers play a role in guiding and correcting the grouting pipe, then the lap-joint lugs on thegrouting pipe are in
lap joint with the lap-joint table, then the lap-joint table is driven to ascend and descend up and down in a reciprocating mode, and smooth flowing of the concrete in the grouting pipe is guaranteed. The cast-in-situ bored pile grouting device and the construction method thereof have the effects of improving the quality of the foundation pile and saving manpower.