The invention discloses an absorption device of acidic material and hydrolysable fluoride in sulfur hexafluoride gas. The absorption device comprises a gas absorption cell and absorption liquid, the absorption liquid is arranged inside the gas absorption cell; the gas absorption cell adopts a vertically arranged slender structure; the absorption liquid adopts sodium hydroxide solution with certain concentration; a plurality of electromagnetic valves which can be arbitrarily opened and closed are arranged on a control pipeline of the gas absorption cell; the bottom of the gas absorption cell is connected with a gas inlet; a pressure reducing valve and a stable-flow valve are further connected with the part between the gas inlet and the bottom of the gas absorption cell; the bottom of the gas absorption cell is further connected with an automatic sample injector and a liquid outlet; the top of the gas absorption cell is connected with a gas outlet; a pressure sensor is arranged at the top of the gas absorption cell. The invention further provides a method for adopting the absorption device of acidic material and hydrolysable fluoride in sulfur hexafluoride gas. The method has the characteristics of high convenience in operation, high absorption efficiency and low solution use level.