The finite-difference time-domain algorithm (FDTD) was used to simulate the optical field distribution of the micro-nano structure target, explore the optical transmission mechanism in the micro-nano structure target, and analyze the influence of material properties and structural parameters on the optical transmission characteristics and optical field distribution. Based on the simulation results of optical field distribution and evolution, the laser transmission characteristics in the nano-wire and nano-pore array targets of semiconductor alumina, insulator silicon dioxide and metal copper with different electrical conductivity are compared, and the modifications of optical field distribution during optical transmission are analyzed. The results show that the optical transmission characteristics and optical field distribution in the target can be modulated by changing the diameter and spacing of the holes (nanowires) in the target structure, and the optical field can be periodically oscillated between the dielectric material and the vacuum region, or transmitted in a stable state. When the laser is transmitted in the copper nanopore array, the light transmittance increases with the increase of the hole radius. Based on the simulation results of light field distribution and evolution, the laser transmission properties of different materials and micro-nano structure targets are compared, the physical images and corresponding phenomena are given, and the micro-nano structure target design is given according to the requirements of light field regulation.