The invention relates to the field of underground mining, in particular to a downward drift filling mining method. In a layered driftway, a drift is divided into a plurality of drifts; the first drift is firstly extracted; after the first drift is extracted and is compactly filled, the rest drifts are sequentially extracted and filled; the layered drifts adopt shallow hole rock drilling, shallow hole loosening blasting or air pick vibration ore breaking, and manual loading and pushing transportation; after each drift is extracted, steel bars are laid on a drift bottom plate; main bars are arranged in a vertical direction; sub bars with the diameter of 8mm are arranged in a direction parallel to the drift direction; then, mortar is poured and irrigated, and drift mortar pad plates are formed; next, tailings, fly ash or tunnel rock filling are carried out; filling bodies are used as support roof plates of the layer; and next, the other drifts are extracted, and the mining mode adopts an one-separated alternate extracting mode. The downward drift filling mining method effectively solves a series of problems of low mining efficiency, high loss and dilution rate, high production cost and the like due to high safety protection difficulty of ore body breaking extraction, and the mining efficiency can reach higher than 91 percent.