In this paper, a THz device based on single-layer metasurface has been designed to generate near-field plasmonic vortex with shifting functionality for increasing THz communication capacity. Based on the geometric metasurface, the shifting of near-field vortex of the device is simulated by FITD (the finite integration time domain). The corresponding results suggest that position shifting of the field distribution in the whole space can be achieved under the illumination of circularly polarized light. To a certain extent, the kind of functional devices can improve the THz communication capacity and can be used in 6G technology.