This utility model relates to the field of rotary drum screen technology, specifically disclosing a rotary drum screen protective device, including a rotary drum screen body, a base plate, support columns, a shock-absorbing structure, a protective cover, and an opening and closing structure. A base plate is provided below the rotary drum screen body, and four support columns are fixedly connected to the upper surface of the base plate. Each support column has a groove on its side surface, and a shock-absorbing structure is provided inside each groove. Protective covers are respectively provided on the upper surfaces of both sides of the rotary drum screen body, and opening and closing structures are provided on the lower surfaces of the protective covers. By providing protective covers and opening and closing structures, the protective covers on the upper surfaces of both sides of the rotary drum screen body can effectively block material splashing from all directions, significantly reducing material waste. The opening and closing structure allows adjustment of the protective cover's state. During normal operation, the protective cover is tightly closed, fully exerting its protective function; when the equipment needs maintenance, repair, or cleaning, the protective cover can be easily opened by controlling the opening and closing structure, greatly improving operational convenience.