The invention belongs to the technical field of mining, and particularly relates to a safe and efficient gently inclined ore body mining method. The method comprises the steps of (1) filling a gob ofan open space room column method stope to form a glue end sand filling body; (2) conducting backstopping on pillars in the gob, in the process of backstopping, firstly conducting the backstopping on rib pillars of the upper row, and after the backstopping of the rib pillars of the upper row is completed, boring obliquely to the adjacent pillars of the next row of the oblique position under the protection of the glue end sand filling body until a row of pillars in the lowermost part of the stope are backstopped; (3) after all the pillars in the gob are fully backstopped, filling unfilled portions of a mountain and the pillar gob in one time; (4) returning to a top mining column and a bottom column from the middle section of a transportation roadway; the method adopts an oblique tunneling method to backstop the next row of pillars in the oblique position, avoids multiple backfilling of the gob adjacent to the the bottom column, ensures the strength of a filling zone adjacent to the bottom column, and ensures the safety of the bottom column during the backstopping.