Abstract: When the sensitivity of a large-size vector hydrophone is calibrated in a standing wave tube, the distribution of the calibration sound field will be uneven, resulting in a large error in the calibration results. In the case that the accurate analytical expression of the calibration sound field cannot be obtained, the sound field simulation analysis model is established based on the actual standing wave tube calibration device. The sound pressure and acceleration values of vector hydrophone and reference scalar hydrophone are obtained by numerical calculation, and the sensitivity correction factor is derived by combining the sensitivity calibration formula and the reference value. After using the correction factor, the maximum absolute error between the test results and the reference value of vector hydrophones with different sizes is reduced to less than 2.0 dB. The results show that the numerical calculation method can effectively reduce the sensitivity calibration error of large-size vector hydrophones caused by the non-uniform sound field and expand the test object of the vector hydrophone standing wave tube calibration device.