It’s difficult to estimate the pitch angle of a target under strong interference with a vertical array by using conventional beamforming(CBF)methods. Aiming at this problem，this paper studied the application of some new methods like hyper beamforming(HBF)and inverse beamforming(IBF). The theoretical basis of the two methods were discussed，and the simulated beam patterns showed that their resolutions were significantly improved compared to CBF. Field measured data showed that，the HBF distinguished the tracks of the target and interference， and the diagonal loading IBF MVDR method could obtain the target’s pitch angle track. This research primitively resolved the problem of pitch angle estimation of weak signal under strong interference，and provided a new approach for underwater weak signal’s localization.
