Hefei Xinqiao International Airport Terminal is a steel structure consisting of long-span rigid frames, with 804m in length and about 161m in width at the widest part. The long-span frame consists of box columns, large curvature beams, tapered box beams and space trusses. The joints between space trusses and box beams named truss-to-box beam connections are the critical parts of the whole structure, because of the discontinuity in geometries and stiffness which result in high stress concentrations and complicated mechanical properties. GJ3-6, GJ3-5 and GJ3-1 of the airport terminal are modeled by ABAQUS. Structure internal forces at six load combinations of bearing capacity limit state are calculated. Lower chords of the landside connections sustain large tensions, while web members of the airside connections sustain large pressures. Since these truss bars are directly connected to cover plate of the box beam, better design details are recommended to reduce the stress concentrations caused by geometrical discontinuity.