The invention discloses an insulation joint. The insulation joint includes a first rail and a second rail which are parallel and are both predetermined lengths, a first isolation compensation unit, asecond isolation compensation unit, a tuning unit and a signal receiving and transmitting unit, wherein, a first endpoint of the first rail separately corresponds to a first endpoint and a second endpoint of the second rail; the first isolation compensation unit is separately connected with the first endpoints of the two rails and can isolate second frequency band signal and can further act a first predetermined capacitive impedance to the first frequency band signal; the second isolation compensation unit is separately connected with the second endpoints of the two rails and can isolate the first frequency band signal and can further act a second predetermined capacitive impedance to the second frequency band signal; the tuning unit is separately connected with middle points of the two rails and the impedance acted to the first frequency band signal is more than a first predetermined value and the impedance acted to the second frequency band signal is more than a second predeterminedvalue; and the signal receiving and transmitting unit is connected with the tuning unit.