Abstract: Through beam - ring beam joint, as a type of joint connecting concrete filled steel tube (CFST) columns and reinforced concrete (RC) beams, has the advantages of clear force transmission mechanism and reduces the material usage and time consumption of welding construction. However, due to the brittleness of concrete, serious cracking problems of reinforced concrete ring beam joints occurs under combined bending, shearing and torsion, which reduces the load-bearing capacity of the joint. To improve the load bearing capacity and optimize the allocation of the ring beam connection, based on a new Reinforced Engineered Cementitious Composite (RECC) ring beam joint, the flexural performance of the ring beam joint is studied and the calculation method of the flexural capacity is proposed. The transfer mechanism of stress and the role of each component for the RECC ring beam connection are analyzed based on the ultimate equilibrium method. A quantitative calculation is performed by analyzing the stress and strain process during the failure stages of ECC on the selected control section to assess the contribution of ECC. By further considering the flexural capacity of the longitudinal reinforcement in the frame beam, ring reinforcement and stirrups in the ring beam, the bending bearing capacity model for the through-beam RECC ring beam connection is proposed. Additionally, a simplified calculation method for the bending bearing capacity of the joint is further proposed taking into account practical engineering considerations by simplifying the control surface. The experimental and finite element results of the two different failure modes are compared with the theoretical formulas, showing good agreement; and the error between the experimental results and the theoretical values is small, proving that the proposed bearing capacity calculation model has certain reliability and theoretical significance.