A heat dissipation device includes a heat dissipation piece, heat conduction plates, a rod piece and a switch. The heat conduction plates are connected to the heat dissipation piece and spaced apart from and arranged parallel to each other so as to define accommodating spaces. Each heat conduction plate has a free end away from the heat dissipation piece, and the free end has a through hole. The rod piece has a first end and a second end opposite to each other, the rod piece penetrates through the through holes, and the second end has a limitation portion. The switch has a cam portion pivoted to the first end. When the switch is pivoted with respect to the heat conduction plates, the cam portion drives the rod piece to move among the through holes, making the limitation portion to press against or be separated from the heat conduction plates.