The invention relates to a high-layering mechanized overhand back mining method including the steps of drill hole layout, ore collapsing and ore drawing. The drill hole layout comprises the steps: firstly, a stope is divided into a slotting area, an auxiliary area and a side collapse area, and the total length of the slotting area and the auxiliary area along the length direction of the stope is equal to the width of the stope; then, 9 central slotting holes with the hole depth of not less than 5.4 m are arranged in the center of the slotting area, wherein 4 central slotting holes are empty holes without loading of explosives, the other 5 central slotting holes are loaded with explosive, and then the periphery of the 9 central slotting holes is provided with a plurality of slotting holes forming an inner circle and an outer circle; a plurality of auxiliary holes arranged in the auxiliary area form a hole net; and a plurality of side collapse holes arranged in the side collapse area form a hole net. The ore collapsing comprises the steps of breaking down an ore by blasting according to a blasting order of the central slotting holes of the slotting area, the slotting holes of the slotting area, the auxiliary holes of the auxiliary area and the side collapse holes of the side collapse area. The back mining method has high back mining height and high mining efficiency, and can effectively realize safe production.