The heat dissipation assembly structure of a power includes a housing having an open upper portion, a power part having one surface supported by the housing, a printed circuit board disposed above the power part and electrically connected to the power part, and a cover member covering the upper portion of the housing and being coupled to the housing, wherein an inner surface of the cover member presses the other surface of the power part in a direction toward the housing to fixedly press the power part between the housing and the cover member.