The invention relates to the field of stirring pile machines and discloses a stirring drill rod. The stirring drill rod comprises an outer pipe and an inner pipe; the outer pipe and the inner pipe are of hollow structures; the inner pipe is sleeved by the outer pipe; the inner pipe and the outer pipe are coaxially arranged; the lower part of the inner pipe gets out of the outer pipe; the upper end of the inner pipe is connected with a slurry supply pump, and a slurry spray nozzle is arranged on the lower part of the inner pipe; a telescopic stirring blade is arranged between the lower part of the inner pipe and the lower part of the outer pipe; the telescopic stirring blade comprises a first blade and a second blade which are hinged with each other; the first blade is hinged with the outer pipe; the second blade is hinged with the inner pipe; and the inner pipe and the outer pipe can oppositely move in the axial direction to drive the first blade and the second blade to oppositely move. The stirring drill rod can ensure the blades to stretch out and draw back, and can guarantee construction according to a designed pile diameter.