Abstract: Four full-scale special-shaped composite steel concrete columns were tested under quasi-static loading, and the hysteretic curve, bearing capacity, displacement and ductility, stiffness degeneration and energy dissipation were analyzed. The results showed that compared with the full-scale special-shaped reinforced concrete column specimens, the addition of steel inside the specimens could slow down the development of cracks and reduce the damage degree of the specimens. Bending failure occurred when the special-shaped column specimen had a large shear-span to depth ratio. When the shear span to depth ratio was small, the shear failure occurred to the specimen. Compared with the full-scale special-shaped reinforced concrete column specimen, on a premise of ensuring the internal reinforcement ratio of the specimen, the addition of steel inside specimens could improve the seismic performance of specimens, including bearing capacity, hysteresis performance, deformation capacity, energy consumption capacity and stiffness degradation rate. When the longitudinal reinforcement ratio of the special-shaped reinforced concrete column was reduced and the steel was added inside specimens, the bearing capacity was improved.