A mercury target installed in a neutron scattering facility is heated instantly by the hitting of 1MW pulsed proton beam. Then, a pressure wave will be generated in mercury, and a target container made of SUS316L could be loaded excessive dynamic stress caused by the pressure wave. The liquid-structure interaction analysis with LS-DYNA code was carried out to make clear behaviors of the dynamic stress, and also to estimate the possibility of the mercury cavitation under the pressure wave propagation. Analytical results showed that the maximum amplitude of the dynamic stress was about 154MPa, which was less than the allowable stress, negative pressure was generated near the beam window, which would cause the cavitation in mercury.