Terminal No. A of Kunming International Airport (TA) is a complex steel-concrete hybrid structure. The airport is located in Kunming, China; the seismic fortification intensity is 8 degree. After multi-analysis, base-isolation technique is applied to the structure, and the terminal will be the biggest base-isolated monomer building in the world after its accomplishment. By using ANSYS, the structural FEM model, which is mainly composed of linear beams elements, linear shells elements and nonlinear isolator elements, was established. Demonstration of isolation schemes and influence of isolator’s layout to the isolation efficiency were firstly introduced. And the selection processes of earthquake waves were introduced. Finally, the elastic time history analysis was carried out to study the seismic performance and isolation efficiency of the structure under the frequently and rarely occurred earthquakes. The results showed that not only the expected shock-absorption goal of ‘reduce 1 degree’under frequently occurred earthquakes is achieved, but also the maximal shear displacement of isolation layer under rarely occurred earthquakes can meet the Chinese code requirements. It is concluded that the design of isolation layer is appropriate; the isolation efficiency of the structure after applying base-isolation technique can meet the challenge.