Abstract: The main proldems including overflow "runs muddy"， subpar underflow concentration， pressure rake and low degree of automation causes the poor grading effect， which directly affects the safe and efficient production of enterprises. In addition to the macro factors from the thickener's own structural parameters， the basic reason for the thickener's classification effect depends on the feed characteristics and reagent action parameters such as mud layer thickness， dosage， overflow solid content， underflow concentration and so on. So the development history， classification and characteristics， existing problems and improvement of thickeners at home and abroad are summarized. The application of automatic rake lifting technology， new feed well structure， automatic dosing technology and integrated control system are systematically analyzed in the aspect of traditional thickeners. The measures of deep cone thickener and inclined plate or tube thickener for stabilization of the bottom flow concentration， improving the material stacking and bonding in the board surface， reducing settlement channel blockage were summarized. The technical characteristics and application of vibration type inclined plate thickening classifier and vibration type inclined plate box thickening classifier are introduced， and the latest technologies and solutions to eliminate the problems of material adhesion and blockage on the inclined plate surface of inclined plate thickener are mainly discussed. The research shows that the thickener will be characterized by high underflow concentration， high treatment capacity， low breakdown rate， low energy consumption and intelligent control in the future. With the help of new materials， automation level， pharmaceutical technology and other technological progress， the main development direction is to continuously optimize the equipment structure， rationalize the specifications and perfect the types based on the traditional thickener and in the direction of high-efficiency thickener. Systematic study on thickener and its high efficiency application provides important ideas for the research and development of general equipment in solid-liquid separation industry in China. It also provides important theoretical and technical support for the realization of efficient dewatering， dry dumping and comprehensive utilization of tailings， and speeding up the process of green mine construction.

Key words: thickener, development process, high efficiency modification, prospect