Abstract: In order to study the migration of mercury in the process of industrial producing activated coke,the laboratory equipment that can simulate the process of industrial preparing activated coke was used to prepare the activated coke sample. And the mercury content of raw coal,carbonized samples and activated coke samples was determined by the mercury detector based on cold atomic absorption spectrometry and the amount of mercury that migrated in the preparing process was calculated. The results show that the mercury content of the raw coal for preparing activated coke is 42. 4 ng/g,the mercury content of the intermediate carbonized sample( TH) is 1. 0 ng/g and that of the activated coke sample( HXJ) is only 0. 8 ng/g. The results show that the form of mercury in raw coal is mainly composed of inorganic salts of covalent compounds and organic mercury in some humic acids,and the decomposition temperature of these mercury compounds is around 350 ℃. While the carbonization temperature can reach 650 ℃,the most of the mercury compounds in the raw coal have been decomposed and escaped to the atmosphere in the form of zero-valent mercury vapor. The carbonization process in preparing activated coke is the largest stage of mercury migration and evaporation,and 97. 6% of the mercury in the raw coal escapes into the air at this stage. In the industrialized process of preparing activated coke,it is necessary to control and remove the mercury emission in the exhaust gas generated by carbonization stage.