Abstract: The surface of the flood discharge building is usually sprayed with polyurea-based coating to improve the impact resistance. However, the research on the debonding failure mechanism of the anti-wear polyurea-based coating under the action of high-speed water flow velocity is still blank. Based on the flow pattern of high-velocity water flow, the mechanical model of high-velocity water flow to flood-discharge building was determined, and the load on flood discharge building caused by high-velocity water flow mainly includes drag force, impact force, fluctuating force and lifting force. The cohesive zone model was used to characterize the debonding failure process of the interface between polyurea-based coating and flood-reducing building, and the debonding failure model of polyurea-coating with high-speed water flow was established, and the finite element formal equations, constitutive relationship, damage initiation principle, evolution principle and contact and collision model of the model are given. The relationship between stress-displacement in the process of debonding failure was obtained by the debonding failure tests, and the variation law between peeling failure stress and inclination angle of interface was obtained. According to the peeling failure test, the parameters of debonding failure model were obtained, and the model was also verified. The test results were in good agreement with the model calculation results, which provides a theoretical basis for the anti-shock and wear-resistant design of flood discharge building.