Heat dissipation device and cold plate heat dissipation system

The invention belongs to the field of heat dissipation equipment and relates to a heat dissipation device and a cold plate heat dissipation system. The heat dissipation device provided by the invention comprises a heat dissipation piece; a first cavity and a second cavity are formed in the heat dissipation piece; a refrigerant passes through the first cavity; liquid exists in the second cavity; the first cavity is provided with a first end and a second end which are opposite to each other; a first opening communicated with the first cavity is formed in the position, close to the first end, of the heat dissipation piece; a second opening communicated with the first cavity is formed in the position, close to the second end, of the heat dissipation piece; and in the direction from the first end to the second end, multiple working modules are arranged on the heat dissipation piece at intervals, a liquid phase part and a gas phase part are arranged in the second cavity, and the horizontal height of the gas phase p