A water-cooling heat dissipation device adopted for a lighting module that includes a plurality of LEDs modulized together, and includes a heat dissipation plate, at least one curved canal recessed inside the heat dissipation plate, at least one inlet formed on one of the sides of the heat dissipation plate selectively, and at least one outlet formed on one of the sides of the heat dissipation plate selectively. The curved canal created as a part of the heat dissipation plate runs laterally and includes at least one bending portion arranged thereon. The inlet and the outlet communicate with the bending portion and a free end of the curved canal in alternative manners, respectively. The lighting module contacts a top of the heat dissipation device directly.