The invention belongs to the fields of coal mining and filling, and in particular relates to a roadway backfill mining method for coal seams with medium-high thickness. The method comprises the following steps: according to a theory of initial roof caving pace of the coal seams and a principle that a filling roadway is smaller than a reserved empty roadway, respectively determining mining width of the filling roadway and the reserved empty roadway; and sequentially mining and filling the filling roadway and the reserved empty roadway in an excavating manner by utilizing a digging-anchoring machine or a continuous miner: firstly mining the filling roadway, fully filling a goaf of the filling roadway with a fluid expansion material, and then solidifying the obtained filling body until the strength is reached; and then mining the reserved empty roadway, and fully refilling or partially filling or not filling the goaf of the reserved empty roadway according to the requirements for protection class of surface buildings. The roadway backfill mining method has the beneficial effects that surface subsidence caused by coal seam mining can be controlled within the minimum allowable degree, recovery rate of coal mining areas 'under three special conditions' (buildings, water and railways) is improved to over 95%, recovery roadways of the mining areas can be reduced, and direct productioncost is lowered.