The utility model provides a shielding device of a primary terminal during radio interference voltage measurement, aiming at solves the problem that: a bare copper wire is coated by aluminum foil paper when the instrument transformer product conducts radio interference voltage measurement, the operation is considerable trouble and time-wasting, meanwhile, the shielding effect is poor. The main points of the shielding device are as follows: both ends of a metallic flexible conduit are respectively provided with a metallic end plug; the outer end of the end plug presents a bolt shape; both ends of the bare copper wire located the inner cavity of the metallic flexible conduit are respectively fixed on the two end plugs; a pair of metallic shielding clamping parts are sequentially screwed into the bolt of the end plug wherein; and the contact surface of the pair of metallic shielding clamping parts is a plane. The benefits of the shielding device of the primary terminal during radio interference voltage measurement are as follows: the operation during measurement is convenient, and the shielding effect is good.