Cast-steel joints characterized in strong adaptability are widely applied in various long span spatial structures. At present, there is no national design specification available on cast-steel joints. Therefore, it is quite a necessity to conduct full-scale test or model test on cast-steel joints suffering complicated forces. This Paper has, taking Nantong Sports Exhibition Center as an example, conducted the experimental study of some important joints, and compared with elastic-plastic nonlinear finite element analysis result. According to the result, the fracture morphology of joints, stress distribution and bearing capacity of joints obtained from the elastic-plastic nonlinear finite element analysis are consistent with those of measured result, proving that the analysis theory applied in engineering design is basically suitable for the actual working condition of cast-steel joints and the joints are sufficiently safe.