Abstract: To solve the application of base isolation technology in nuclear power, based on the structure of a high temperature gas-cooled reactornuclear power plant, a 1:20 scale model earthquake simulation shaking table test was conducted to study the earthquake response rules and characteristics of horizontal bi-directional and three-directional earthquakes on the horizontal isolated nuclear structure (including equipment), including the structure of the acceleration and displacement response and floor response spectrum, equipment response, and isolation effect. Results show that the first two modes of the isolated structure are horizontal translation, the deformation is mainly concentrated in the isolation layer, and the superstructure is nearly translational. Considering the vertical input, the acceleration amplification factor in the structual horizontal direction is 2-3 times the horizontal two-way input, and the vertical acceleration response larger. The horizontal peak is much smaller than the vertical peak of the floor response spectrum, and the three-way input peak is larger than the two-way input peak of the vertical response spectrum. The earthquake reaction of the equipment are basically similar to the structure. In short, the horizontal isolation can effectively reduce the horizontal seismic response of the structure and equipment, however, has no damping effect on the vertical response, and the vertical seismic action may reduce the horizontal isolation effect.