The invention provides an isolation-grounding combined switch and an isolation static contact support conductor thereof. Heat dissipation efficiency and a heat dissipation effect of the combined switch can be improved and working stability is ensured. The isolation-grounding combined switch comprises a shell. A moving contact support conductor is arranged in the shell, a moving contact is arrangedon the moving contact support conductor in a guiding mode, and the moving contact is provided with a grounding end and an isolation end. An isolation static contact support conductor is also arrangedin the shell, the isolation static contact support conductor comprises a support conductor main body and a static contact seat arranged on the support conductor main body in a protruding mode, and the static contact seat is used for being matched with the isolation end of the moving contact. The support conductor main body is provided with a top part located at a top of the static contact seat and a bottom part located at a bottom of the static contact seat, and an inner concave space is formed between the static contact seat and the top part and/or the bottom part of the support conductor main body. An outer peripheral surface of the static contact seat is provided with radiating ribs located in the at least one inner concave space.