The invention discloses a water-cooled heat dissipation device. The water-cooled heat dissipation device comprises a heat dissipation body and a plurality of heat dissipation columns. The heat dissipation body comprises a base and a cover plate, wherein the base and the cover plate can be buckled with each other. The base is provided with a water inlet, a water outlet and a containing cavity communicated with the water inlet and the water outlet. The multiple heat dissipation columns are arranged in the containing cavity. Friction stir welding or electron beam welding or vacuum brazing sealing is adopted between the base and the cover plate. The water-cooled heat dissipation device has the advantages that the structure that the heat dissipation columns are arranged in the containing cavity or on the side face of the cover plate and can be buckled in the containing cavity, friction stir welding or electron beam welding or vacuum brazing sealing is adopted between the base and the cover plate for sealed connection is adopted, so that the sealing effect of the whole water-cooled heat dissipation device can be improved, and the service life of the water-cooled heat dissipation device is prolonged.