Abstract: Bowtie aperture has been widely applied in the realm of nanometer direct-writing lithography for obtaining focusing spots beyond the diffraction limit. However, the obtained spot is elliptic-shape for the Bowtie case, which impacts the applications of the Bowtie structure. Double Bowtie aperture, as a novel nano-lithography structure, is proposed to attain circle-symmetric focusing spots beyond diffraction limit. The results demonstrate that circle-symmetry spots can be obtained, and the electric field intensity of transmission light is 22 times of that of incidence. By combining the double Bowtie structure with metal-insulator-metal, the propagation length of the enhanced transmission light is obviously prolonged.