Abstract: The study aims to investigate the ultimate strength behavior of ship hull stiffened plates with crack defects under extreme axial cyclic loading through model testing. The test model is a double-stiffened plate specimen, which is designed to be more practical for engineering applications while maintaining measurement accuracy. Seven model conditions are set to discuss the effects of crack distribution, accumulative plastic residual deformation, and loading mode on the ultimate strength of the double-stiffened plate. Finite element simulation results are supplemented for comparison. In the test, the ultimate strength of the stiffened plate with symmetrically distributed cracks across the stiffeners is the largest. The ultimate strength of the stiffened plate decreased by about 40% after three cycles of loading when considering the accumulative plastic residual deformation. While without considering the residual deformation, the decrease in ultimate strength after three cycles is only within 10%. The reduction is also around 10% when tensile load is included in the cycles. This indicates that the main load-bearing area of the stiffened plate is near the stiffeners, and accumulative plastic residual deformation under extreme axial cyclic loading has a significant impact on the ultimate strength of the stiffened plate. The tensile load in the cyclic loading has an enhancing effect on the ultimate strength of the stiffened panel.