The invention discloses a device for treating aluminum phosphide reaction tail gas. The device comprises a sedimentation cooling chamber, a spray absorption tower and a plurality of packed absorption towers. The sedimentation cooling chamber is provided with a cooling chamber tail gas exhaust outlet and a spray device; distributors are arranged on the tops of the packed absorption towers, packed tower alkali liquor input ports and packed tower tail gas output ports are formed in the tops of the packed absorption towers, packed tower tail gas input ports are formed in the lower portions of the packed adsorption towers, and packed tower alkali liquor alkali storage tanks with packed tower alkali liquor output ports are arranged at the bottoms of the packed absorption towers; a spray tower alkali liquor input port and a spray tower tail gas input port are formed in the top of the spray absorption tower, a sprayer is arranged on the upper portion of the spray absorption tower, a falling film absorber and a gas-liquor separator are arranged on the lower portion of the spray absorption tower, and a spray tower alkali liquor alkali storage tank with a spray tower alkali liquor output port is arranged at the bottom of the spray absorption tower. The device has the advantages that the tail gas can be qualified to be discharged, alkali liquor obtained after the tail gas is absorbed can be utilized for preparing phosphate products, accordingly, the aluminum phosphide reaction tail gas can be comprehensively treated, and the device has excellent economic and environmental protection benefits.