Coal tar pitch, a kind of artificial pitch, is generally viscous liquid, semi-solid or solid. It is black and shiny. In the process of coal tar processing, the residue after the liquid fraction is removed by distillation is called coal tar pitch. Coal tar pitch is the main component of coal tar, accounting for 50%~60% of the total amount. Generally, it is believed that its main components are polycyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons and their derivatives.The specific composition of the compounds is complex,and the difference of raw coal types and processing technology will also lead to the difference of components, The current method is mainly based on the softening temperature.