The utility model discloses a hole washing device for geological hole construction. The device comprises a hole washing sprayer connected with a high-pressure water conveying pipe, four sets of nozzles are symmetrically arranged on the end face of the sprayer, the included angle between the central axis of each set of nozzles and the central axis of the sprayer is 45 degrees, an inner cavity of the sprayer is of a stepped reducing structure from the inlet end to the nozzle end, and a protruding steel pad is arranged on the outer wall of the sprayer in the axial direction of the sprayer; duringapplication, a reverse backwash spray head can be combined for construction and cleaning treatment, and fixed-rotation, rotation and swing reciprocating type flushing is conducted on the half lengthof the lower half section of the pore-forming cavity in the hole bottom direction and the half length of the upper half section of the pore-forming cavity in the hole opening direction through a forward high-pressure spray head and a reverse high-pressure spray head; the hole cleaning spray head pushes part of rock slag and rock blocks to the two sides of the walking area in the walking process until the full-section cavity is cleaned up; meanwhile, the hole washing construction process is implemented in the hole, so that the potential safety hazard of high-pressure water flow in the hole washing process is avoided; protruding steel pads are symmetrically arranged on the outer wall of the spray head in the axial direction of the spray head to prevent drill jamming and protect the drill bitfrom drilling.