Abstract: Cleaning of lignite usually entails difficulties in handling the large amount of high ash slime because of the mingling with high-ash roof and floor and interbanded lignite during the course of its mining,and the tendency of lignite to undergo degradation in water.In order to meet the needs for upgrading and reduction of ash of lignite,a comprehensive analysis is made of the approach for treating the lignite discarded at the South Open Pit,Huolinhe,Inner Mongolia.Experimental study conducted indicates that the use of pneumatic dry cleaning method makes it possible to dispense with the slurry water treatment system as in the case of using wet cleaning method.And with the incessant improvement and mature of the methods for dry cleaning of low-andmedium-calorific-value lignite,mass quantity of low-grade lignite can be converted through upgrading to superior-quality coal for enhancing the utilization rate of coal resources.