An LED lamp structure with high-efficiency heat-dissipating function includes a heat-dissipating module, a light-emitting module, a power-transmitting module, and a casing module. The heat-dissipating module has a plurality of heat-dissipating fins, and the heat-dissipating fins are combined together to form a radial shape and a receiving space. The light-emitting module is received in the receiving space of the heat-dissipating module. The power-transmitting module is electrically connected with the light-emitting module. The casing module has a top board body, a bottom board body mated with the top board body, and a joint board body disposed between the top board body and the heat-dissipating fins. Both the top board body and the joint board body have an opening for exposing the light-emitting module. Each heat-dissipating fin has a top side contacted with the joint board body and a bottom side separated from the bottom board body by a predetermined distance.