Abstract: The basic theory and numerical method of bond-based peridynamics are introduced, and the accuracy of the numerical calculation of peridynamics is verified by Kathoff-Winkler test and finite element simulation of plate with round holes. Then the quasi-static fracture test and numerical simulation of peridynamics of high-manganese austenitic steel stiffened plate are carried out to verify the accuracy of the numerical simulation. Finally, the effect of stiffness ratio on the failure mode of double-stiffened plate is studied. The results show that the numerical simulation result of peridynamics is in accordance with the quasi-static fracture test result, and that the stiffness ratio affects the propagation sequence of crack in different regions and the crack speed. The experiment reveals the crack propagation mechanism of the double-stiffened plate, and provides a new simulation method for the fracture of stiffened hull plates.