The invention provides a device for realizing joint signal transmission which is mainly composed of an insulation covering (1), a conductor bar (2), a spring (3) and a conductor ring (4). An axial hole is in combining part of two joints, and the insulation covering (1), the conductor bar (2), the spring (3) and the conductor ring (4) are installed in the axial hole respectively, the conductor bar(2) is covered installed in inner cavity of the isolation covering (1), the insulation covering (1) prevents the conductor bar (2) and the conductor ring (4) from contacting with joint, the insulation covering (1) has step inside, the conductor bar (2) has step on exterior surface, the insulation covering (1) inner cavity step and the conductor bar (2) exterior surface step are installed with spring (3), and keep contact state with the conductor bar (2) and conductor ring (4), the conductor bar (2) connects with signal transmission wire respectively, thereby, signal transmission of joint can be realized.