For the convenience of engineering design on T-shaped, L-shaped, and cross-shaped concrete filled steel tubular (CFST) columns, a unified algorithm for eccentric-loaded capacity of special-shaped CFST columns was developed through an analysis of calculation methods in the typical specifications. The N-M relationship curves of columns were calculated and analyzed by using a self-complied numerical analysis method. The validity of the algorithm was then verified by experimental results in other literatures for various cross-section forms of special-shaped CFST columns. The results show that the uniform algorithm has clear mechanical meaning and it is easy to operate. The mean ratio of the test result to prediction of load bearing capacity is 1.1~1.4, with a certain safety reservation, but the prediction accuracy depends on the engineering axis direction of loading cross-section. The proposed unified algorithm improves the computational theories for special-shaped CFST columns, which can promote its developments and applications in the practical engineering.