Abstract: To predict the moment-rotation relation of an easy-repairing concrete-filled steel tubular (CFST) rectangular column-steel beam frame joint with S-shaped damper, a three-parameter exponential model is proposed upon its initial rotational stiffness, flexural capacity, and shape parameter. The calculation formula for the initial rotational stiffness of the joint is derived from the component method; and the calculation formula for flexural capacity is derived from the plastic limit analysis method. The tension four-hinge mechanism and the compression three-hinge mechanism in the plastic limit state of S-shaped damper are proposed. Regression analysis of the test results and finite element parameter analysis results yield the correction factor of the flexural capacity and shape parameter of the joint. To simulate the practical application of easy-repairing joints, quasi-static cyclic tests and finite element parameter analysis are conducted on steel frame-steel plate shear wall structure specimen containing easy-repairing joints with S-shaped dampers. The connection between the beam and column in the finite element analysis model adopts the three-parameter model. Compared with results of quasi-static cycle tests, of finite element parameter analysis for joint specimens, and of structural specimen tests, the three-parameter exponential model can effectively simulate the skeleton curve of the easy-repairing joint with the S-shaped damper.