In order to study the anti-progressive collapse performance of the base-isolated step-terrace structure, a 4-span 3-story plane frame was simulated to verify the reliability of the LSDYNA computing platform. Then, in compliance with the national specifications, six basic isolation and step-terrace system frames and one ordinary flat isolation structure were designed, and the collapse resistance of the remaining structure was studied based on the demolition method to obtain the load coefficient and the vertical displacement curve of the failure point. The results show that when the lower grounded corner column(support) and the upper grounded corner column were removed, the anti-collapse ability of the flat ground isolation structure was greater than that of the base-isolated step-terrace structure; when the upper ground support was removed, the anti-collapse ability of the flat ground isolation structure was weaker than base-isolated step-terrace structure. Furthermore, the resistance mechanism of the failure span of the bottom support(bottom column) adjacent to the sill lagged behind the resistance mechanism of the upper ground span. Our study provides reference for the anti-progressive collapse design of the base-isolated step-terrace structure.