The utility model discloses a hole wall processing device for improving the hole forming quality of a cast-in-situ bored pile, which comprises a machine body, an insertion hole is formed in the middleof the machine body, an inner sleeve is fixed on the wall of the insertion hole, an electromagnet is fixed on the inner sleeve, an outer sleeve is rotatably connected to the outer wall of the machinebody, and a plurality of hole wall processing units are hinged to the outer sleeve; compared with a drilling hole-forming process, the hole wall processing process has the advantages that the disturbance to engineering is small, and no negative effect is caused to the hole wall. The shape of the hole wall can be reshaped, the hole wall with the rough hole wall and the spiral surface is formed, meshing between the surface of a pile body and the surface of a soil layer around the pile is improved, the pile side friction resistance is brought into full play, the pile forming quality is improved,and the method is particularly suitable for friction piles and end-bearing friction piles which are widely used at present.