Abstract:The special T-shaped composite columns with concrete-filled square steel tubulars have good mechanical properties. Taking the length, eccentricity and eccentricity direction of the specimen as the test parameters, nine specimens with different slenderness ratio are designed for eccentric compression test. By observing the failure mode of the specimen, the load-strain curve and load-deflection curve are obtained, and the influence of each parameter on the eccentric compression performance of the specimen is analyzed. The test results show that the strength of 600 mm long specimens is damaged. The specimens with lengths of 1 500, 1 800 mm are broken by bending instability; the longer the specimen length is, the more obvious the bending failure characteristics are; the larger the eccentricity is, the lower the eccentric bearing capacity is; the eccentricity direction has a relatively small impact on the eccentric compression performance. It is found that compared with the calculation results of relevant specifications, the results calculated by DBJ / T 13-51-2010 are in good agreement with the test results. The ductility of special T-shaped composite columns with concrete-filled square steel tubulars is well, the square steel tubes can work together, and the eccentric compression performance is good.