The disclosure provides a heat dissipation device, including an enclosure, a connective member, and a fan module. The enclosure includes a first cover body and a second cover body that are opposite to each other. The second cover body includes an opening. The connective member is connected to one of the first cover body and the second cover body in the enclosure. The fan module is movably connected to the connective member, and is configured to move between a first position and a second position relative to the enclosure based on the connective member. When moving to the first position, the fan module is located in the enclosure.