Abstract: To study circular section concrete filled carbon fiber reinforced polymer (CFRP)-steel tube (CFRP-ST/C) under bending-torsion load, 9 specimens were designed for static test under bending-torsion load. The characteris-tics of torque-rotation angle (T-θ) curve and shear stress-strain (τ-γ) curve were studied. Following the experimental study, the T-θ curve and deformation mode of the specimen were simulated by ABAQUS and compared with the test results. The good consistence between numerical results and experimental ones reveals that the proposed simulation method can predict the behavior of CFRP-ST/C reasonably and accurately under bending-torsion load. In addition, the influence of layers of CFRP, material strength, bending ratio and steel ratio on the static behavior of CFRP-ST/C specimens under bending-torsion load were then studied through numerical parametric study. Finally, equations for predicting the bearing capacity of CFRP-ST/C were proposed. The average value of calculation results for torsional bearing capacity of members/test results of torsional bearing capacity of members (T_ft^c/T_ft^t) is 0.998, and the mean square error is 0.038. The average value of calculation results of torsional bearing capacity of members/finite element results of torsional bearing capacity of members (T_ft^c/T_ft^f) is 0.973, and the mean square error is 0.051.