External electromagnetic shielding device

An external electromagnetic shielding device for being disposed outside of a test system, comprising:

• a bottom shield configured to be arranged under a bottom of the test system;
• a conductive cover being in a grid-like shape and arranged above the bottom shield, wherein the conductive cover includes:
• a top shield spaced apart from the bottom shield along a height direction by a distance;
• a lateral shield connected to the top shield, wherein the lateral shield, the top shield, and the bottom shield jointly define an electromagnetic shielding space;
• and
• a plurality of supports fixed to the lateral shield, wherein any two of the supports are spaced apart from each other along the height direction, and wherein the supports include a bottom support that is in an annular arrangement;
• and
• a rolling module including a rolling unit and a linkage unit that is connected to the rolling unit and the bottom support, wherein, when the linkage unit is coiled on or released from the rolling unit, the linkage unit moves the bottom support so as to allow the lateral shield to fold or unfold between the bottom shield and the top shield along the height direction.