Abstract: The acceptance integral approach is applicable for calculating the root mean square of structure response under random loading. The theoretical basis and application conditions of the acceptance integral approach were studied, and the approach was combined with the finite element method to simplify the calculation process and also make it easy to implement. The flow-induced vibration responses of the core barrel were calculated using the combined method and the test values of the fluid fluctuating pressure of scaled model test of core barrel. The calculation results are consistent well with the test ones.