Abstract: In order to reduce the corrosion of inorganic salts from emulsion water in the coal tar to the fractional distillation condenser and accelerate the separation of coal tar from water,the desalination test of coal pyrolysis tar was carried out by chemical demulsification. The feasibility of chemical demulsification of coal pyrolysis tar was discussed.The effects of test conditions such as demulsifier type,demulsifier addition,water addition,desalination temperature and residence time on the desalination of coal tar were investigated.The results show that the self-made polyether demulsifier has better desalination effect.The addition of demulsifier and water are with amount 100×10~(-6) and 15%respectively,and the desalination temperature is 110 ℃,the salts content in the oil are obvious decreased. The residence time has little effect on the result within a certain range.Therefore,the self-made polyether demulsifier,which is mainly attributed to the strong interaction with special structure of asphalt in coal tar,demonstrates better desalting effect comparing with the other two kinds of widely used demulsifier.