The invention provides an isolation-grounding combination switch and a GIS. The problem that a combination switch in the prior art is complex in structure can be solved. The isolation-grounding combination switch comprises a shell, a moving contact supporting conductor is arranged in the shell, and a moving contact is arranged on the moving contact supporting conductor in a guiding mode; the moving contact is provided with a grounding end and an isolation end; and the isolation-grounding combination switch further comprises an isolation static contact and a grounding static contact which are arranged corresponding to the two ends of the moving contact respectively. The shell is provided with an installation hole used for installing the grounding static contact, and the grounding static contact is fixed at the installation hole through a insulating support member. The shell is provided with an inclined wall part which is arranged in an inclined manner and is opposite to the grounding end of the moving contact, so that the installation hole is positioned in the axial direction of the isolation end of the moving contact for the moving contact to be inserted into the installation holewhen the grounding switch is switched on; the plugging portion of the grounding static contact used for plugging cooperation with the moving contact is located in the installation hole, and a shielding structure used for shielding the grounding static contact is formed on the inner wall of the corresponding position of the installation hole.