Casing for electric system computer protective device

The utility model relates to a casing for a protective device of a microcomputer in an electric system, wherein, a box body of which has a fully sealed integral structure, and a panel is movably connected with the box body and can be fixedly sealed by screw bolts. With the structure, the protective device of a microcomputer can be free from the influence of dust, moisture, harmful gas, electromagnetic interference, etc., and can be directly installed on abominable job sites, which alters the requirements that the protective device of a microcomputer must be installed in a sealed main control room that needs to be provided with air conditioners in the past. The method that the inner part of the box body adopts slots to install pluggable units makes equipment maintenance and component exchange more convenient.