Abstract: According to the on-site inspection data and the operational version provided by the principal, the structural security and the anti-seismic appraisal of the building with adding 1 steel structure extra-floor were done, identification results showed that the building had not special fortification, local inter-story displacement angle exceeded the limited value and beam-column overreinforced, it was proposed that riders should be added between local columns, expanding section of partial columns of the first layer, so as to meet the requirements of the current seismic and relevant specifications.As a lifeline project of this sort of building with adding steel structure extra-floors, it was also discussed the related issues in process of the aseismic appraisal and reinforcement design, which provided references for similar projects or further discussion.