The utility model discloses a protection device of terminal equipment. The device comprises a panel arranged at the front end of the device, a back plate opposite to the panel, an upper shell arrangedat the upper end of the device, a bottom plate opposite to the upper shell, and a side shell arranged on the side surface of the device, a detachable door with a visual window is arranged on the panel; the upper shell is provided with an opening and a cover plate capable of covering the opening; heat dissipation strips are arranged on the side shells; a base is arranged on the bottom plate, a supporting column is arranged on the base, and a connecting plate is arranged on the supporting column and connected with the bottom plate. Through the arrangement of the window, the problems of a built-in device in the using process can be observed, the internal situation can be accurately judged, once the problems occur, the problems can be found immediately, the window can be opened when faults occur due to the arrangement of the detachable door, the whole protection device does not need to be detached, and inspection and maintenance are more convenient.