The present invention relates to a responsive gas insulated bus (GIB) support structure. To this end, the present invention comprises: a support; a speed-responsive unlocking part provided at an upper part of the support and having a shape in which a guide is exposed from the both sides thereof; and a bracket which is disposed at a flange of a tank and to which the guide coupled. In the present invention, therefore, when deformation of the structure is large or slow upon the occurrence of a length change due to pressure variation or heat, the speed-responsive unlocking part for supporting the structure is configured to maintain an unlocked state and thus fully absorb the deformation amount to prevent the structure from being deformed and broken.