The structure of dock-typed navigation-locks is under complex loads and is prone to cracks near the chamfering of the riverside lock wall. When the anchorage length of reinforcing bars is designed to be the minimum value according to the current hydraulic industry code, the crack propagation path may bypass the anchorage extension sections and even cause collapse accidents. Here, a simulation model of the navigation-lock structure was established using the extended finite element model (XFEM) to study the cracking law of dock-typed navigation-locks with the consideration of cumulative damages, and the improvement measures for the anchoring of reinforcing bars were put forward. The results show that considering cumulative damages, the crack propagation paths of the reinforced concrete lock chambers are all in or near the tensile stress area of the plain concrete lock chamber under the same loads. When the anchorage lengths of the reinforcing bars near the chamfering are designed to be the minimum value of the code, the crack propagation paths in some damage situations under the loads would bypass the anchorage extension sections of reinforcing bars near the chamfering of the lock chamber, resulting in the failure of meeting the requirements of the ultimate bearing capacity of the structure. When the lengths of the anchorage extension sections of reinforcing bars are stretched beyond the tensile stress area of the plain concrete lock chamber, and the exceeding parts are equal to the minimum value of the code, the anchorage extension sections can be made to pass through the crack propagation path, and the crack extension length and the maximum tensile stress of the reinforcing bars can be reduced to meet the requirements of the ultimate bearing capacity. The study results can provide a basis for the accident prevention and control of the navigation-lock structure, and for the further revisions of relevant design codes.