The invention discloses a device and process for safely treating aluminum phosphide fumigating residues. The process comprises the steps that firstly, inert gas is introduced into a hydrolyzing and absorbing tank, air in the hydrolyzing and absorbing tank is discharged, then water is injected into the hydrolyzing and absorbing tank, then a hydrolyzing agent, the aluminum phosphide fumigating residues and a site absorption agent are sequentially added to the hydrolyzing and absorbing tank, and absorption liquid is sprayed for absorption in an exhaust absorption device; and secondly, reaction liquid generated after a hydrolyzing reaction is conducted is discharged and filtered, filter residues are neutralized and buried safely, filter liquid returns to the hydrolyzing and absorbing tank to replace the water added to the hydrolyzing and absorbing tank in the first step, residual liquid is absorbed by exhaust to complement the insufficient part, and raw materials are added for a next reaction. According to the device and process, the hydrolyzing reaction is performed in the hydrolyzing and absorbing tank, exhaust absorption comprises site absorption in the hydrolyzing and absorbing tank and further absorption in a two-stage exhaust absorption tower, and the residual liquid absorbed by exhaust can be reused for hydrolyzing agent preparation.