An electrical enclosure with a great heat dissipation and an ingress protection rating equal or greater than level 65, including a sealed enclosure housing and a heat bridge configured inside the sealed enclosure housing. The sealed enclosure housing includes a heat-absorbing layer, a reinforced layer and a heat dissipating layer. The heat bridge can be a gaseous heat bridge or a solid heat bridge. One end of the heat bridge is connected to the heat-emitting electrical components configured inside the sealed enclosure, and the other end is connected to the heat-absorbing layer on the sealed enclosure housing. The generated heat is rapidly conducted to the heat-absorbing layer on the enclosure housing through the heat bridge, and then conducted to the heat dissipation layer through the reinforced layer. The heat is dissipated to the exterior space through such structure to keep a suitable temperature inside the sealed enclosure.