The utility model relates to the technical field of cofferdam drainage, particularly to a pipe-shaped adjustable drainage opening. The pipe-shaped adjustable drainage opening comprises a plurality of horizontal pipes (3) which are laid in backfilled earth (1) and a cofferdam (2) side by side, wherein vertical pipes (4) vertically welded with the horizontal pipes are arranged at the water inlet ports of the horizontal pipes (3); flanges (5) are arranged at the top ends of the vertical pipes (4); the vertical pipes (4) are sequentially connected with a plurality of short sections (6) used for adjusting the height through the flanges (5); and mask boards (7) used for sealing the pipes are arranged on the top surfaces of the short sections at the topmost ends or the top surfaces of the vertical pipes (4). The pipe-shaped adjustable drainage opening provided by the utility model can flexibly adjust the height of the drainage opening as required, the drainage opening can control the water level at the filling zone through the adjustment of the releasing flow, the maintenance is easy and the drainage is stable.