Activated coke is an efficient and low-cost adsorbent for purifying flue gas pollutants with good crushing strength and renewable properties, which can use in power plants and other industries to remove pollutants from flue gas. It is the core material of dry flue gas purification technology, which can meet the development requirements of green economy and circular economy of our country. In this paper, the research progress of activated coke applied in flue gas pollutant removal was reviewed, the preparation, activation, modification, characterization and engineering application of activated coke were introduced, and the removal mechanism of several pollutants (SO2, NOx, Hg0, VOCs) on activated coke was summarized. The related factors affecting the adsorption properties of activated coke and the research results of recycling process of waste activated coke were summarized. At present, activated coke can be prepared by mainly physical activation and chemical activation. Physical activation mainly uses water vapor and other gases under high temperature conditions to make activated coke have a porous structure, while chemical activation is mainly through acid, alkali, salt solutions to impregnate the activated coke, optimize the pore structure of activated coke, enrich functional groups on the surface, provide more adsorption sites for activated coke, in order to improve the ability of activated coke to remove flue gas pollutants. The pollutants have undergone physical and chemical adsorption processes on activated coke in the process of activated coke adsorption of pollutants. Some pollutants are directly physically attached onto the surface of activated coke, while some pollutants will be affected by adsorption conditions and functional groups of activated coke, and chemical reactions will occur at the adsorption site and be converted into other recyclable or harmless substances. Among them, SO2 in flue gas is usually converted to H2SO4, NOx is easily catalytic converted to N2, Hg0 can be converted to HgO or HgSO4, and VOCs will eventually be converted to CO2 and H2O. The activated coke can complete the removal of flue gas pollutants through a series of adsorption and transformation processes. In order to further improve the engineering application capacity of activated coke, the adsorbed activated coke can also be reused through washing, heating, microwave and other ways. The improvement in the cyclic adsorption performance of activated coke by the conditions and methods of regeneration have been studied extensively. As the adsorption conditions of activated coke (adsorption temperature, flue gas components, etc.) and other influencing factors are gradually in-depth studied, the efficiency of pollutant removal of activated coke has been greatly improved, and the better adsorption performance of activated coke can reach more than 90%. In addition, with the preparation process of activated coke becomes gradually mature, activated coke has a better synergistic adsorption effect on pollutants, and has been used to a certain extent. The engineering application of activated coke at home and abroad was also summarized, and some problems and prospects of this technology were put forward, so as to provide reference for the research and application of activated coke in the future.