Located in Dongchangfu District of Liaocheng City, Dongchang Shuyuan Culture Center is a steel structure building with one underground floor and four aboveground floors. Due to the need of building facade modeling, the building has various sizes of overhangs (1m-11.30m), and there are design difficulties such as super-long structure, non-negligible temperature effect, large openings on some floors, small effective width of floor slabs, and the existence of local leaping columns, which bring greater challenges to the structural design.For the larger overhangs, different structural solutions were selected for trial calculation according to different lengths of overhangs, and a comparison was made in terms of economy, safety and applicability, and technical measures, such as outriggers, overhanging trusses and hanging columns, were adopted to solve the problems of overhangs of different sizes in the structure in a targeted way. In view of the problem of over-length structure, the necessity of analyzing the temperature stress of the floor slab of the steel structure house with large-sized concrete floor slabs was demonstrated, the weak parts of the floor slab were found out and strengthened according to the results of the analysis of the temperature stress, and the measures to reduce the temperature stress of the floor slab were also given. The seismic performance design was carried out, and the columns of the skip-floors for solving the cantilevering problem were set as the key components, the standard for seismic fortification was to maintain elasticity under frequently occurred earthquakes and moderate earthquakes, and not yield under rarely occurred earthquakes, and the reaction spectrum calculations and the rare earthquake elastic-plastic time-course analysis were used for the calculation to guarantee the seismic performance under moderate earthquakes and rarely occurred earthquakes, and the damage and elastic-plastic displacements of the whole structure under rarely occurred earthquakes are also examined. The results showed that: the bearing capacity of the overhanging structure could be improved simply by increasing the cross-section size of the overhanging members, but the improvement was limited, and the over-sized cross-section was not only uneconomical, but also seriously affected the net height of the building, the method of changing the force transmission path, setting up the overhanging trusses and hanging columns could effectively improve the bearing capacity of the overhanging structure, and reduce the cross-section size of the members to improve the economy; when the building plan size was large, the temperature stresses near the opening of the top floor slab on the first floor exceeded the standard value of tensile strength of concrete, so reinforcement should be carried out and measures should be taken to reduce the temperature stress; the key components in the structure could achieve the set performance targets under fortification earthquake and rare earthquakes, and the structure as a whole suffered less damage under rarely occurred earthquakes, with an elasticity-plasticity displacement angle less than the normative limit value.