Heat dissipation device and microwave oven

The utility model relates to a heat dissipation device and a microwave oven. The heat dissipation device comprises a first heat dissipation shell, a fixing piece and an extrusion piece. The extrusion piece is arranged on the first surface of the first heat dissipation shell and protrudes out of the first surface. When the heat dissipation device is used, the heat dissipation device is fixed on the to-be-cooled equipment through the fixing piece, at the moment, the fixing piece can apply certain pressure to the extrusion piece, and then the extrusion piece presses the first heat dissipation shell on the surface of the to-be-cooled equipment, so that the sealing performance between the first heat dissipation shell and the surface of the to-be-cooled equipment can be effectively improved; therefore, leakage of heat dissipation gas is avoided, and more heat dissipation gas can enter the first heat dissipation channel from the gas inlet of the first heat dissipation shell. At the moment, the heat dissipation gas i