An electrical connection device comprises an electrical connector. The electrical connector comprises: an insulative body; a plurality of conductive terminals provided to the insulative body; a metal shell surrounding the insulative body and an outer shielding member. The metal shell comprises a top portion, two openings respectively formed at two sides of the top portion and two first ground pieces positioned opposite to a side where the top portion is present and extending outwardly respectively from the two openings. The outer shielding member comprises a main body transversally provided on the top portion of the metal shell and covering the two openings and two second ground pieces respectively extending outwardly from two ends of the main body, the two second ground pieces each have a penetrating hole penetrating from a top surface to a bottom surface. At least a part of each penetrating hole of the two second ground pieces receives the corresponding first ground piece. By that the outer shielding member covers the two openings of the metal shell, EMI may be prevented from being produced.