slag. A large amount of carbon-ash complexes in the coal gasification slag formed under the conditions of high - temperature meltingand complex reaction atmosphere. Grinding is an important method to dissociate the residual carbon in the slag. However, the particle sizeof the grinded slag is too small to use conventional separation process to extract carbon. Air classifier can achieve efficient separation of ultrafine particles by utilizing the centrifugal force and aerodynamic drag of different particles in the vortex to generate different directionsof movement for classification. Based on this, a dry carbon extraction process by grinding the gasification slag was proposed and then theair classifier was used to separate residual carbon and ash. Through the design of uniform test and the regression analyses of the influencingfactors, the optimal experimental conditions were obtained and the experimental results were verified. The results show that the airflow classification is influenced by the coupling effect of multiple factors, among which the frequency of the classifier and the frequency ofthe induced draft fan are the key factors affecting the carbon extraction effect, the optimum experimental conditions were the frequency ofthe classifier 175 Hz, the frequency of the induced draft fan 5 Hz, the frequency of the feed screw 5 Hz, and the opening of the secondaryair valve 90°. The predicted value of the LOI of the carbon-rich products obtained under this condition (49.64%) is consistent with theexperimental results (49.76%);Under the optimal conditions, the D of the carbon rich product obtained by airflow classification is 5.95 μm,canbe used as a rubber reinforcement filler to replace carbon black and white carbon black; The calorific value is 16.73 MJ/ kg, which can befully used as fine powder fuel. Moreover, airflow classification can achieve good decarbonization effect of gasification slag, and the resulting decarburization slag has a loss on ignition of less than 10%, which is beneficial for its application in the field of building materials andother fields. The grinding crushing airflow classification method can achieve the separation of gasification slag, which is beneficial for itsdownstream utilization.