Abstract: Zhundong coal( ZD) has a high content of alkali metals( especially Na and Ca),and its direct combustion as steam coal will cause serious boiler contamination and slagging. The hydrothermal upgrading method can effectively remove alkali metals from coal and can also improve the physical and chemical properties of coal,therefore,it has been widely studied. However,hydrothermal upgrading will also generate a large amount of waste liquid,resulting in the loss of organic matter and low energy efficiency of raw materials,which limits the application of this method. In response to the above problems,the hydrothermal upgrading technology was coupled with the waste liquid gasification technology,and the experimental research on the hydrothermal upgrading of ZD and the derived waste liquid catalysis on the hydrothermal reactor and the self-made two-stage reactor was carried out. The distribution characteristics of the three-phase products after upgrading and the catalytic gasification characteristics of the waste liquid were also explored. The results show that as the hydrothermal temperature increases,the solid recovery rate of coal samples decreases,and the total organic carbon( TOC) and gas products in waste liquid increase significantly,but at least 97.8% of carbon elements are distributed in solid phase products. Catalytic gasification of waste liquid produces combustible gas rich in CH_4 and H_2,with the highest proportion reaching 70%. It is found that Ni element in Ni/C catalyst plays a catalytic role in the gasification of waste liquid. The catalytic efficiency increases with the increase of hydrothermal temperature and vaporization temperature,and decreases with the increase of liquid hourly space velocity. The preferred catalytic gasification experimental conditions are: Ni/C catalyst,hydrothermal temperature of 300 ℃,catalytic gasification temperature of 350 ℃ and liquid hourly space velocity of 150 h-1. In short,the combined technology of hydrothermal upgrading-waste liquid catalytic gasification technology( HT&CHTG-Process) can not only realize the modification of coal quality,but also recover the energy in the waste liquid,which can provide new ideas for the clean and efficient utilization of ZD.