Abstract: A trailer cable connector structure, particularly a plug-formed connector, includes an insulation casing having a plurality bores axially extending therethrough to each receive and fix a conductive bar therein. The casing also has a plurality of radial openings in communication with the bores. Each of the conductive bars has a first cavity and a second cavity respectively formed on two axial ends thereof, the first cavity being adapted to receive a terminal pin of a mating socket therein and the second cavity having an inner circumferential groove and being sized to receive an conductive pin therein. The conductive pin has a wire physically and electrically connected thereto.