Abstract: The existing researches on response and dynamic tensile failure of asphalt concrete core wall under spatial oblique incidence of seismic waves have great shortcomings. By considering the arbitrariness of SV-wave incident azimuth and oblique incident angles and constructing the non-uniform free field on foundation boundary based on the wave field superposition principle, an input method for spatial oblique incidence of SV waves is established. Then, an empirical formula for the change in instantaneous tensile strength of asphalt concrete with strain rate is established based on the test results. A new method for the safety evaluation of core wall based on instantaneous tensile stress and strength is proposed. Finally, the influences of incident azimuth and oblique incident angles on the acceleration and stress distributions of core wall are analyzed. The damage mechanism of core wall caused by tensile stress surge caused by spatial oblique incidence is revealed. Using the proposed method, the error of the traditional static strength judgment method for core wall damage is demonstrated. The distribution characteristics of tensile failure zone of core wall under different incident modes are clarified. The results show that compared with those under vertical incidence, the acceleration of core wall in water flow, dam axis and vertical directions can be increased by 54%, 9.2 times and 5.2 times at most under spatial oblique incidence. The tensile stress of core wall can be increased by a maximum of 14.2 times at most. Neglecting the spatial oblique incidence severely underestimates the accelerations and stresses of core wall. The more the incident direction deviates to dam axis direction and the larger the oblique incident angle, the more easily the tensile failure at the wave-facing side of core wall occurs. The traditional static strength judgment method leads to a large error of tensile failure of core wall.