The invention discloses a surface plasmon enhancement volcanic-vent 3D vertical structure LED structure and a preparation method thereof. The method is characterized by preparing volcanic-vent surfaceplasmons on the p-GaN surface to couple a three-dimensional quantum well light-emitting array, and introducing the surface plasmons to the vertical structure LED structure to couple quantum wells through a volcanic-vent interface, so that not only internal quantum efficiency of the vertical structure LED structure can be improved through coupling between the surface plasmons and the quantum wells, but also carrier injection efficiency of the surface plasmon enhancement LED device can be improved greatly through the volcanic-vent coupling; and besides, through 3D arrangement design of the volcanic-vent morphology and the quantum well light-emitting array, exciton energy in the light-emitting region is allowed to be coupled to the surface plasmons more favorably, and then, photons are radiated out and emitted from the surface of the device, so that light extraction efficiency of the vertical structure LED device can be enhanced. The 3D multi-functional composite vertical structure LED structure has a practical popularization and application value.