Abstract: In order to quantitatively study the flexural performance of the DCJS, the validated finite element model was established based on the test results of the DCJSs. Subsequently a series of finite element models were used to systematically study the deformation and force mechanism of the DCJS under eccentric load. The flexural performance of the DCJDs was analyzed through the parameterization method. Based on the outcomes of the parametric study, the moment-rotation model was established for DCJS. Results show that the flexural performance of the DCJS decreases with the increase of eccentricity, wedge height and midrib height, and increases with the increase of wedge length, wedge width, channel thickness and tube wall thickness. Meanwhile, the moment-angle curve, initial flexural stiffness and plastic flexural capacity of the DCJS can be accurately predicted by the moment-rotation model.