Abstract: High energy density fuel is the key to provide power support for new high performance aircraft,and its synthesis and application research has important prospective and strategic significance.Coal is the main energy source and important raw material in China.Coal-based oil obtained by direct conversion of coal fully retains the special ring molecular chemical structure of coal,has good thermal stability and high energy density,and is considered to be the preferred fuel for hypersonic aircraft.In this paper,coal-based high energy density fuel was obtained by enriching light aromatics,Diels-Alder chemical synthesis,catalytic hydrogenation stabilization and product separation and purification from naphtha fraction produced by direct coal liquefaction process.The molecular structure and properties of the product were characterized and evaluated.The experimental results show that naphtha fraction by direct liquefaction of coal is an excellent catalytic reforming raw material.After catalytic reforming,light aromatics are enriched,and the content of aromatics is as high as 71.05%.The main products of Diels-Alder chemical synthesis have two-or three-ring configurations in closed space,and the content of which is about 46.18%,due to the large tension energy in molecules,the structure is compact,and it has a larger density and calorific value of volume.The density and volumetric calorific value of synthesized coal-based high energy density fuel is 0.899 0 g/cm3 and 38.06 MJ/L respectively,which greatly exceeds the current domestic petroleumbased jet fuel(RP3 and RP6),coal-based jet fuel,US and Russian military standards.However,compared with synthesized high energy density fuels (JP10 and T10) from a single pure substance,it is still relatively small.The main reason is that the enrichment of light aromatics is only 71.05%,which can further improve the content of light aromatics.In addition,the types of coal-based high energy density fuels are complex,and the content of main products is 46.18%.The next step is to adjust the molecular configuration and purification of the synthesized products.