The invention discloses a tanning waste treatment device and a treatment technique using the device. The treatment device comprises a pyrolysis gasification furnace, a pyrolyzing furnace, a combustible gas purification system and a fume purification system, wherein the pyrolysis gasification furnace and pyrolyzing furnace are respectively a double-layer rotary kiln; the pyrolysis gasification furnace comprises a scrap leather feed port, a scrap ash discharge port, a first high-temperature crude combustible gas outlet and a first high-temperature fume outlet; the pyrolyzing furnace comprises a leather sludge feed port, a sludge ash discharge port, a second high-temperature crude combustible gas outlet and a second high-temperature fume outlet; the outer cylinder of the pyrolysis gasification furnace and the outer cylinder of the pyrolyzing furnace are provided with at least one combustible gas burner; each combustible gas burner comprises a central sprayer, an internal ring sprayer, an external ring sprayer and a cooling component which are coaxially sheathed from inside to outside; the cooling component is annularly arranged on the outer side of the bottom end of the external ring sprayer; and a cyclone is respectively additionally arranged in the central sprayer and external ring sprayer. The treatment device disclosed by the invention enhances the energy utilization efficiency and reduces the heat loss.