An interference-proof electrical plug connector has an insulative housing, two terminal sets, a shielding-grounding plate and a shell. The terminal sets are mounted in the insulative housing and each terminal sets has multiple conductive terminals. Each terminal set has multiple conductive terminals and at least one pair of super-speed signal terminals. Each super-speed signal terminal has a mounting section including a widening tab laterally protruding from the mounting section toward an adjacent super-speed signal terminal to reduce the distance between the super-speed signal terminals of the pair. The shielding-grounding plate is mounted in a rear end of the insulative housing. The widening tabs of each pair of the super-speed signal terminals effectively diminish impedance of the super-speed signal terminal such that input loss and return loss of the super-speed signal terminals are reduced.