The invention relates to an improved drainage tube fixing device which comprises a fixing base (1), wherein medical water suction swelling sponge (8) is connected inside the fixing base (1); a locking pressing cover (4) is connected with a drainage tube fixing base (3); and a drainage tube clamping device (5) is in matching connection with the inside of the drainage tube fixing base (3). The improved drainage tube fixing device is characterized in that the medical water suction swelling sponge (8) is provided with a through hole (8a); an alpha spiral cut (8b) is arranged between the edge (8c) of the medical water suction swelling sponge (8) and the through hole (8a); and the alpha spiral cut (8b) penetrates through the upper and lower end surfaces of the medical water suction swelling sponge (8). The improved drainage tube fixing device is good in university and applicable to drainage tubes of different tube diameters; and the medical water suction swelling sponge can sufficiently wrap the drainage tube and can absorb the seepage around a drainage conduit in time, and the parts around the skin cut are maintained in a relatively clean environment, so that the wound is prevented from infection and is convenient to take care.