The invention relates to the field of flywheels, in particular to a dual-mass flywheel with a waterproof structure. The dual-mass flywheel comprises a main flywheel, an auxiliary flywheel and arc-shaped springs, wherein the main flywheel and the auxiliary flywheel are separated from each other in the axial direction, and the arc-shaped springs are installed in grooves formed in the outer side of the main flywheel in the radial direction. The main flywheel comprises water drainage holes, wherein the water drainage holes penetrate through the main flywheel in the axial direction, and inlets, facing the auxiliary flywheel, of the water drainage holes are located in the inner sides of the arc-shaped springs in the radial direction. An annular water blocking ring which extends from the main flywheel to the auxiliary flywheel is arranged on the outer sides of the inlets of the water drainage holes in the radial direction. By the adoption of the technical scheme, the dual-mass flywheel which is excellent in water resistance is provided.