Abstract: To study the mechanical properties and constitutive relation of DSS (duplex stainless steel) S22053 under cyclic loading, specimens machined from S22053 hot-rolled steel plate were tested under monotonic and cyclic loading patterns. Based on the monotonic curves, the material mechanical properties under monotonic load were analyzed. The material parameters of the Chaboche model were obtained using the results of the specimens with constant strain amplitude, and the test curves were simulated by the finite element software ABAQUS. The results reveal that DSS S22053 has good ductility and low proportional limit. No obvious yield platform or yield point was observed. The cyclic backbone curve can be well fitted with the Ramberg-Osgood model. The three types of combined parameters calibrated by different component models can simulate the hysteresis curve of materials well, and the three-back stress component model (N2L1) has the best fitting effect. The results can be used to analyze and calculate the mechanical performance of DSS structures under seismic load.