Abstract: The present disclosure relates to the technical field of waste water treatment, and provides a device and a method for controlling diffusion of MPs (Microplastics) carried with ARGs (Antibiotic Resistance Genes) in a waste water treatment system. The device includes a water collection tank arranged on a mounting rack, a collection assembly arranged inside the water collection tank and used for collecting MPs carried with ARGs in waste water, and a treatment assembly arranged inside the water collection tank and used for removing the collected MPs carried with ARGs in waste water. According to the method, sorting treatment for the MPs carried with ARGs in waste water is realized effectively with an air flotation principle and an electric separation principle. The device is simple in integral structure, and has the advantage of convenience in mounting.