The invention discloses a wet type double-clutch unit which comprises an odd-numbered shaft clutch and an even-numbered shaft clutch, wherein the two clutches work independently; each clutch comprises a diaphragm spring which is contacted with a hill-like supporting bulge of an axial pressing disc, and the axial pressing disc is forced by deformation of the diaphragm spring to move axially, so that a friction plate below the axial pressing disc is compressed to transmit power to dual discs. The wet type double-clutch unit has the advantages as follows: compression force is transmitted through deformation of the diaphragm springs, and compared with the conventional compression force transmission under hydraulic control, higher response speed is provided during gear shifting; the structure facilitates mounting, and the wet type double-clutch unit has good reliability and fatigue durability.