The invention discloses a water-cooling heat dissipater with adjustable dustproof devices.The water-cooling heat dissipater comprises a framework.Fixing supports are arranged on the left side and the right side of the framework respectively.Installing holes are formed in the fixing supports.A first water chamber is arranged above the framework.A second water chamber is arranged below the framework.The first water chamber is provided with a water inlet.The water inlet is provided with a filter screen and a water chamber cover.The second water chamber is provided with a water outlet.The water outlet is provided with a water chamber cover.A heat dissipating core is arranged in the middle of the framework and comprises a heat dissipating tube and fins.The heat dissipating tube is arranged between the first water chamber and the second water chamber.The fins are uniformly arranged on the outer side of the heat dissipating tube.The fixing supports are provided with the dustproof devices.Each dustproof device comprises a dustproof frame, a dustproof piece and a supporting shaft, wherein the dustproof piece is horizontally arranged on the dustproof frame and arranged above the heat dissipating tube correspondingly, and the two ends of the dustproof piece are fixed to the dustproof frame through telescopic supporting shafts.The dustproof devices are arranged, dust is blocked on the dustproof pieces, and therefore the problem that dust on the heat dissipating tube and the fins is inconvenient to clean can be solved.