The invention relates to a vortex tube device for separating moisture and light hydrocarbons of natural gas through condensation, and belongs to the technical field of gas refrigeration and gas-liquid separation. The vortex tube device is additionally provided with a liquid discharging structure and a separation recovery unit. Therefore liquid drops condensed through rotational flow in a vortex tube flows out of the vortex tube in time through the liquid discharging structure, and are prevented from being evaporated again in the tube to return to gas flow, so that the separation efficiency of the moisture and the light hydrocarbons is greatly improved. In addition, the pressure difference in different positions of the device is ingeniously used, so that gas flowing out of the tube together with condensation liquid can automatically return to cold gas flow of the vortex tube after gas-liquid separation; the recovery is realized. The vortex tube device has the advantages that the structure is simple; the use and the maintenance are convenient.