A surface wave excitation device includes a transmission line disposed on a wire layer PCB, and a same quantity of layers are respectively disposed above and below the wire layer PCB. A copper wire is disposed on each layer of PCB, and the copper wire forms a closed region. Closed regions on the PCB that are respectively disposed above and below the wire layer PCB and that have a same distance from the wire layer PCB are in a same shape, and a closed region on a PCB farther away from the wire layer PCB occupies a larger area. The wire layer PCB includes first and second closed regions, the first closed region is disposed on one side of the transmission line, and the second closed region is disposed on the other side, and shapes of the first and second closed regions are mutually symmetrical with the transmission line as a symmetry axis.