The scope of this review is to highlight the potential contribution of Ranque-Hilsch vortex tube in meeting the requirements of energy efficiency improvement, low-grade sustainable energy utilization and waste heat regeneration with its unique energy separation effect in industry. Ranque-Hilsch vortex tube has been received more and more attentions in recent years, as it meets requirement of energy conservation with its energy saving and environmental friendly operating modes nowadays. Vortex tubes has been famous for the unique energy separation phenomenon and the ability of obtaining the instant cooling and heating effects with air as the most common working fluid, which had been widely exploited. The vortex tubes have been widely adopted by industries on different energy performance enhancement purposes as energy regeneration or recovery. The functions that the vortex tubes play are plenty. Besides the sole single gas-phase, there may be phase changing process involved in vortex tubes, and the purposes of vortex tubes adopted may be divided into mainly energy separation and mainly mass separation. The mass separation process in vortex tube is more complex, as the phase change and component separation will be interrelated together. The main objective of this paper lies in the analysis, carding and construction of application and operation mechanism of vortex tubes from the more and more newly emerging research focuses, to derive a clear classification and promising technique hotspots. Thus the main content is divided into two parts to summarize and discuss. Firstly the energy or temperature separation in which the hot or cold fluid stream produced by vortex tube is the main purpose, and secondly the mass separation in which the mass or component separation usually accompanying with phase change and temperature variation is produced by vortex tube. In each part, the operation mechanism, system configuration, performance influencing factors and nowadays technique status are introduced and described.