Heat radiation module

The utility model relates to a heat radiation module, which is suitable for a portable electronic device. The heat radiation module comprises a first grill, a casing seat and a fan, wherein the first grill is arranged on the bottom of the machine casing of the portable electronic device and is provided with a plurality of first hole gaps, and the casing seat is provided with an air inlet, a second grill, a containing space and an air outlet, wherein the second grill is arranged on the top of the casing seat and is provided with a plurality of second hole gaps, and the hole diameters of the second hole gaps are smaller than the hole diameters of the first hole gaps. Under the condition of being consistent with the safety control, the heat radiation efficiency of the portable electronic device can be increased by changing the sizes of the hole diameters of the first grill and the second grill. In addition, the first grill and the second grill are respectively formed into a whole on the bottom of the machine casing and the top of the casing seat, so the production cost of the portable electronic device is reduced.