The invention provides an opencast and underground combined mining method of steeply inclined
coal seam groups; the detailed implementation method comprises the following steps: opencast construction is carried out downwards in a certain angle along the inclined direction of the steeply inclined
coal seam group, the construction is conducted to reach a certain distance deeper than that when the first
coal seam appears, then horizontal construction is conducted until all of the steeply inclined coal seam groups are penetrated, and then the construction is continued back to the surface of the earth at a certain angle; at the location with a certain distance below the coal seam, another construction gallery is dug and penetrated through along the trend of the coal seams; transportation equipments are arranged in a laneway, the laneway is used for placing top coal or other
coal mining methods are adopted, the coals mined are carried into the construction gallery by the laneway transportation equipment, and then are transported to a mine
coal plant. The opencast and underground combined mining method of the steeply inclined coal seam groups solves a plurality of problems such as high mining cost and
low resource recovery rate and the like in the opencast of the steeply inclined coal seam groups, simultaneously solves the problems such as low safety, high labor intensity, low efficiency and high cost and the like during the underground mining of the steeply inclined coal seam groups, causes the opencast mining to become underground mining and the underground mining to become opencast and ensures the
complementation of the strengths and weaknesses, thus being a safe and highly efficient
coal mining method of the steeply inclined coal seam groups and having good social benefit and economic benefit.