煤炭开采、发电、煤化工等工业中产生的煤基固废存量大、增量多、利用率低已成为制约宁东基地绿色低碳、高质量发展的瓶颈。井下绿色充填是无害化、资源化、规模化处置利用多源煤基固废的有效途径。本文以宁东基地为试验区，分析了多源煤基固废的污染风险、理化性质和多重属性，系统阐述了煤基固废用于井下充填的基础理论和技术体系。研究表明：（1）煤矸石、粉煤灰、脱硫石膏等污染性和理化性质符合填埋标准(GB 18599-2020），气化渣、炉底渣等固废的部分重金属含量超过筛选值，可采取技术措施降低潜在污染风险，多源煤基固废可用于井下绿色充填。（2）煤基固废用于井下充填的基础理论包括绿色充填可行性评价、煤基固废充填材料性能、充填材料与环境多场耦合机理、多层位立体充填机制。（3）多源煤基固废井下绿色充填技术体系主要包括煤矸石源头减量精准开采技术、井下采选充协同技术、煤基固废重金属吸附与络合钝化技术、多源煤基固废充填材料制备技术、充填材料长距离管道输送技术、充填全过程智能监测技术等。最后，根据宁东基地任家庄矿地质条件，提出并实施了超前钻孔注充低位充填，展望了集成活性粉体制备、高值建材研发、生态修复治理、井下绿色充填等煤基固废多产业链接协同利用新模式。

The large stock，large increment and low utilization rate of coal⁃based solid waste generated in coal mining， power generation， coal chemical industry and other industries have become a bottleneck restricting the green， low⁃carbon and high⁃quality development of the Ningdong base. Underground green backfilling is an effective way for harmless，resourceful and large⁃scale disposal and utilization of multi⁃source coal⁃based solid waste. Taking the Ningdong base as the pilot area，this paper analyzes the pollution risk，physicochemical properties and multiple attrib⁃ utes of multi⁃source coal⁃based solid waste，and systematically expounds the basic theory and technical system of coal⁃ based solid waste for underground backfilling. The research shows that:1 The pollution and physicochemical proper⁃ ties of coal gangue，fly ash，desulfurization gypsum，etc. conform to the landfill standard (GB 18599—2020)，and the content of some heavy metals in gasification slag，furnace bottom slag exceeds the screening value，and the po⁃ tential pollution risk can be reduced by taking some technical measures. Multi⁃source coal⁃based solid wastes can be used for underground green backfilling. 2 The basic theory of coal⁃based solid waste for underground backfilling in⁃ cludes the feasibility evaluation of green backfilling，the characteristics of backfilling materials from coal⁃based solid waste，the multi⁃field coupling mechanism between backfilling materials and the environment，and the multi⁃ layer three⁃dimensional backfilling mode.3 The green backfilling technology system of multi⁃source coal⁃based solid waste mainly includes precise mining technology of coal gangue source reduction，integrating underground mining⁃sepa⁃ rating⁃backfilling coordination technology，heavy metal adsorption and complex passivation technology for coal⁃based solid wastes，preparation technology of backfilling materials from multi⁃source coal⁃based solid waste，long⁃distance pipeline transportation technology of backfilling materials， intelligent monitoring technology of whole backfilling process，etc. 4 Finally，according to the geological conditions of the Renjiazhuang Mine in the Ningdong base，ad⁃ vanced borehole backfilling and low⁃level backfilling are proposed and implemented. The new multi⁃industry chain col⁃ laborative utilization mode of coal⁃based solid waste is prospected， which integrates the preparation of active powder，the research and development of high⁃value building materials，ecological restoration and treatment，and under⁃ ground green backfilling.