Abstract: Spiral separator is a kind of traditional thin flow membrane separation equipment. Due to the rapid development of mining and coal industry,as well as the urgent demand of solid waste treatment at present,spiral separator is paid attention to for its advantages of low energy consumption,simple structure,high efficiency and low operating cost. In this paper,the theoretical research progress of spiral separator was discussed,including the flow field,spiral separation process,process optimization and intelligent control of spiral separator,and the separation characteristics and application status of coal spiral separator were summarized,and the new design and application of spiral separator were introduced. For the research of flow field on the spiral separator,some new testing methods have been introduced. However,it is difficult to measure the distribution of the longitudinal velocity and radial velocity in the thin film area,especially in the inner edge at present. The numerical simulation provides a convenient method for studying the influence of structural parameters and operation parameters on the flow field,but the simulation accuracy needs to be further improved.In the research of the spiral separation process,the positron emission particle tracking technology is a breakthrough in the theoretical research of spiral separator,which is used to detect the movement of particles in the spiral separator. The numerical simulation of particle movement in the spiral separation process provides a convenient means for the qualitative analysis of the spiral separation mechanism. However,due to the neglect of many practical conditions in the simulation process,there is still a big gap between the simulation results and the test results. At present,the research on process optimization and intelligent control of spiral separator is still in its infancy. In recent years,a number of new spiral separators have been developed at home and abroad. Some progress has been made in reducing the separation density: MTI company in South Africa has developed a spiral separator with low separation density. When the production rate is reduced by about 4%,the separation density can be reduced from 1.61 g/cm~3 to 1.54 g/cm~3. Moreover,a kind of composite trough spiral separator with an ultra-low pitch to diameter ratio( inner edge cubic parabola,outer edge ellipsoid) has been designed in China. The separation density can be reduced to 1.543 g/cm~3 when the gangue is predischarged in the roughing stage. Compared with the spiral separator with the traditional parameters of an ellipse and cubic parabola,the separation efficiency of the composite trough spiral separator has been increased by 19.41% and 13.11% respectively when the ash content of clean coal is equivalent. In the future,the research focus of spiral separator is mainly to use advanced means,such as PEPT technology and numerical simulation technology,to further study the influence of structural parameters( groove shape,pitch diameter ratio,and other structural parameters) on the flow field distribution characteristics and separation process of spiral separator. Meanwhile,it is necessary to cooperate with the improvement in structure,technology,and application of new materials to improve the separation accuracy and to make a breakthrough in the scope of density control.