Abstract: Facing the severe ecological problems brought by the increasing land degradation in the coal mining areas and the difficulties on the defining of the scope of coal-covered surface in the open-pit mining areas, a normalized difference coal mine index (NDCMI) was proposed based on the spectral characteristics of typical water bodies, vegetation, bare land and coal piles in the coal mining areas as well as the band characteristics of Landsat 8 remote sensing data. The NDCMI value of the ground object samples was used to set the threshold value to distinguish and identify the ground object information of the coal pile and the mining area. The results show that:First, consisting of blue, red, near-infrared and mid-infrared bands of Landsat 8, the NDCMI method was applicative to the Xiaolongtan mining area; Second, from 2013 to 2018, the area of the Buzhaoba open-pit mining area increased by 1.03 times, while the area of Xiaolongtan open-pit mining area decreased by 42%; The gravity of coal mining activities in Xiaolongtan mining area showed a spatial trend from northeast to southwest and the trend from Xiaolongtan open-pit mining area to Buzhaoba open-pit mining area, which greatly increased the pressure on ecology and environment of the Buzhaoba open pit mining area.