Lignite has rich resources, low price, many pores, rich functional groups, mainly phenolic hydroxyl, high reaction activity, short activation time and other characteristics. Based on the advantages of lignite properties, the preparation of activated carbon from lignite has attracted much attention. Lignite based activated carbon is widely used in industrial gas purification, wastewater treatment, coal based electrode and supercapacitor. As lignite has low calorific value and high pollutant emission, it is of great significance to prepare high value-added activated carbon from lignite. The pore structure, specific surface area and pore size distribution of activated carbon restrict the development of lignite based activated carbon. In order to enhance the adsorption capacity of activated carbon, different preparation methods were used to adjust the pore structure. The properties of lignite and the main factors affecting the properties of lignite based activated carbon, including raw materials, coal blending and lignite briquetting conditions, are reviewed. The preparation methods of activated carbon from lignite include chemical method (hydrochloric acid, phosphoric acid, potassium hydroxide), physical method (steam, carbon dioxide and flue gas) and physical chemical method (chemical gas combined activation and microwave assisted chemical activation). The mechanism of different preparation methods of lignite activated carbon was described. The problems in preparation of activated carbon from lignite were prospected.