The utility model discloses an earthing switch predelivery test device, move moving the collateral branch seat and being used for hanging the quiet collateral branch seat of static contact of side subassembly including what be used for bearing earthing switch, be equipped with the removable fixed pedestal mounting portion of base that supplies to move the side subassembly on moving the collateral branch seat, be equipped with the overhang on the quiet collateral branch seat and at the static contact hanger of pedestal mounting portion top, be equipped with on the overhang position of static contact hanger and supply the removable fixed static contact installation department of static contact. Through moving collateral branch seat and quiet collateral branch seat simulation earthing switch fabricating yard, move the required installation basis of side unit mount with moving the simulation of collateral branch seat promptly, the required pipe generating line of static contact hanger simulation static contact installation with quiet collateral branch seat top, distance between use static contact installation department and the pedestal mounting portion is the distance of the required extension of foldable grounding switch blade, thereby can be before earthing switch dispatches from the factory, test foldable grounding switch blade's extension length on this test device, improve earthing switch's ex factory pass rate.