Abstract: By utilizing an external diagrid frame and an inner reinforced concrete core-tube, the diagrid-core tube structure forms a tube-tube structure with strong lateral stiffness. This structure form has been widely used in super high rise building structures. The seismic response results of the model structure with different seismic fortification levels have been obtained by the simulated earthquake shaking table test. Based on the empirical and analytical methods for the seismic reliability analysis of structures, the failure probabilities of the structure with different seismic fortification levels were analyzed, and the seismic performance and reliability of the diagrid-core tube structure system are studied. The shaking table test results show that the inclined columns in the layer where the section sizes of the structural members of the diagrid are changed were damaged before the inclined columns in the substructure. Furthermore, a shaking table test-based probabilistic seismic fragility analysis method was put forward. The damage probabilities of the prototype structure under different seismic fortification levels have been studied. The probabilistic seismic fragility level of the diagrid-core tube prototype structure system is obtained.