Objective The exploitation of mineral resources has brought about a series of ecological and environmental problems, and there is currently limited research on the evaluation of large−scale mine ecological restoration. This paper assesses the mining ecological restoration of the Sanjiang metallogenic belt in Yunnan province, using remote sensing monitoring results and regional natural geographic data.

Methods The evaluate system includes four mine exploitation indexes (land occupation type, mining method, mineral species, and pollution type) and six physical geography indexes (altitude, slope, aspect, land cover type, rainfall, and illumination time). Using the Analytic Hierarchy Process (AHP) method, the study area has been divided into severely affected zone, heavily affected zone, moderately affected zone, and minor affected zone, whose areas are 80.68 km², 3356.80 km², 6640.84 km², and 174569.36 km², respectively, accounting for 0.4%, 1.8%, 3.5%, and 94.1%, respectively.

Results The mining ecological problems of the severely affected zone include serious damage to landform caused by large−scale open−pit mining, geological disasters caused by high and steep slope of stope, and serious land and water pollution caused by sulfur and heavy metals.The ecological restoration of heavily affected zones should mainly focus on the extensive damage to vegetation and land resources caused by large−scale open−pit mining, as well as the acidification and heavy metal enrichment of water and soil caused by long−term accumulation of solid waste. Themining ecological problems of the moderately affected zone are mainly the occupation of land resources caused by transfer sites and solid waste, as well as the damage to landscape caused by mining. In the minor affected zone, the mining activities are mainly mining architecture, and are of small scale and distribute sporadically, which have minor effects on the ecological environment ofmines.

Conclusions This study explores the establishmentof anassessment system applicable to large−scale mining ecological restoration. By clarifying the miningecological problems in different affectedzones, targeted suggestions can be provided for carrying out mine ecological restoration, which is expected to provide data support and scientific basis for relevant government departments to manage mine ecological restoration work.