The mining has come into the deep in Suncun coal mine.In order to achieve the maximum recovery of retained safety coal pillar and solve the problem of gangue emission,the experimental study was made on paste-like gangue slurry filling by gravity.The testing results indicated that paste-like gangue slurry conforming to the design requirements can be prepared.The paste-like gangue slurry filling by gravity not only is economical but is favorable to environmental protection,this gravity-flowed filling technology provides the technical support for Suncun coal mine to realization green production and sustainable development.