The invention discloses a multifunctional inflatable experiment device for innocuous treatment of metal particles in the field of high-voltage power transmission line testing equipment in an electric system. The multifunctional inflatable experiment device mainly comprises a cylindrical metal cavity, an electrode module, an organic glass window, an inflating and deflating module and experiment function modules. The organic glass window is hermetically fixed by two ends of the cylindrical metal cavity through a flange, an electrode is fixed in the middle of front-end organic glass window to form a coaxial cylindrical electrode system, and a cylindrical body of the cavity is provided with an inflating and deflating hole which is connected with the inflating and deflating module. Experiment function module mounting positions are arranged on the inner wall of the cavity, so that rapid replacement of various function modules can be achieved. The multifunctional inflatable experiment device has the advantages of small electric field distortion, experiment function switching convenience and safety, simplicity and convenience in observation, can be used for experiment researches on alternating/direct-current voltage environments and metal particle innocuous treatment measures such as electrode film lamination, insulator properties and particle trap, and offers strategies for metal particle pollutant prevention and control under actual working conditions.