Abstract: In order to solve the harm of heavy metal release behavior in coal to environmental pollution and human health,the effects of the occurrence mode on migration behavior of heavy metal during coal separation,combustion,gasification,and pyrolysis processes was analyzed.The results show that the heavy metal in mineral phase can be removed greatly with the decrease of ash content in separation process,while the heavy metal in organic phase can't be removed easily.In the high temperature conversion process of coal,the organicbound heavy metal are more volatile than mineral-bound heavy metal,and the volatility of latter is affected by mineral types. The occurrence mode of heavy metal in coal are direct and indirect which can be combined with many methods.It is believed that the study of the occurrence mode and migration behavior of heavy metal helps to control the pollution caused by heavy metal during coal conversion process from the source,and the occurrence mode of organic heavy metal elements can be better revealed by pyrolysis process.