Abstract: Objective The Muli mining area, located in the Qilian Mountains of Qinghai Province, is the source of the Datong River, which is a crucial tributary of the Yellow River. This area lies within the high - altitude permafrost zone, featuring an ecologically sensitive and vulnerable environment. In the early 21st century, unregulated coal mining activities severely damaged the local ecosystem. After the closure of the No. 4 Mining Well, four major ecological restoration challenges surfaced: the steep and unstable slopes of the waste - rock hills, significant waterlogging in the mining pit, damage caused by permafrost excavation, and the occupation of land by waste rock and debris, which led to the destruction of grasslands. Methods From a geological restoration standpoint, efforts are made to mimic the original geological structure and characteristics. For diverse geological bodies, ecological geological layers are constructed and reconstructed. In engineering - based ecological governance, a variety of ecological geological restoration techniques have been implemented. For instance, the middle part of the rear edge of the south debris hills is subjected to roof cutting and load reduction. On the surface of debris hills, a hard-soil base layer is built. The excavation pit wall is transformed into a stepped or platform - shaped slope. In the eastern part of the pit bottom, backfilling is executed, accompanied by the restoration of the frozen soil layer. The accumulated water in mining pits is managed to form plateau lakes. On the slopes of debris hills and mining pit, an artificial soil layer is laid, followed by grass-covering on the surface. The ecological restoration work of the mine has effectively re-shaped the post-mining topography and geomorphology of the No. 4 Mining Well area. The total area of this governance project amounts to 16,703,100 square meters. A cumulative volume of 1.4687 million cubic meters of backfill soil has been completed, and the grass-covered area totals 2.968 million square meters. Results and conclusions After three years of dedicated ecological restoration initiatives, the slag mountain within No. 4 Mining Well has attained comprehensive stability. The artificial soil, ingeniously engineered using slag materials, has provided a propitious environment for the robust growth of native grass species. Moreover, the surface water quality has been maintained at a good level. A new plateau landscape has been formed, which has realized the overall natural integration of the topography, the ecological environment, and the surrounding environment. This accomplishment offers invaluable successful experiences and serves as a practical reference for the conservation of ecological barriers in high-altitude frigid zones and the implementation of ecological restoration projects in other regions.