Abstract: In order to cope with the low comprehensive utilization rate of coal gasification slag (CGS) and the environmental and carbon emission pressure caused by landfill，a systematic review is carried out on the current situation that the key problems such as high encapsulation and low activity of carbon ash in CGS hinder its effective recovery and utilization.The research focuses on the physical and chemical proper⁃ ties and microstructure analysis of CGS，as well as the combing and evaluation of the current carbon ash separation technology and modification process，aiming to explore its application potential as a“carbon-sil⁃ icon”dual-source material in the field of polymer fillers.By modifying the activated carbon residue compo⁃ nent，CGS can partially or completely replace similar fillers such as carbon black to realize its high-value application in polymer materials.It is proposed that by constructing route for integration of“quality-modifi⁃ cation-high value”，the separation and modification process can be effectively integrated，and the coal gas⁃ ification slag is expected to be included in the category of environmentally friendly polymer material fill⁃ ers，promoting the transformation of coal gasification slag from end treatment to green functional materials.

Key words: coal gasification slag, carbon ash separation, polymer material filler, resource utilization