An electronic module includes a substrate, a metallic shielding cover, an electronic component and a piezoelectric element. The metallic shielding cover is disposed on the substrate and forms an accommodating chamber together with the substrate, wherein the metallic shielding cover has an opening, and the accommodating chamber is communicated with outside via the opening. The electronic component is disposed on the substrate and accommodated in the accommodating chamber. The piezoelectric element is adhered to the metallic shielding cover, wherein the piezoelectric element after being enabled is configured to bring a local portion of the metallic shielding cover for vibrating to change the volume of the accommodating chamber. In addition, a heat dissipation module is also disclosed.