Abstract: Filtering anti-jamming performance of polarization sensitive array, based on oblique projection filtering technology, was theoretically studied for dual message signal under completely polarized situation. Through the full rank characteristics of signal polarization vector, the required oblique projection filtering operator was built. Interference signal was suppressed and the complete desired signal was retained by the specific operationproperties. In this paper, the operator of dual message signal filtering was deduced by matrix operation, like matrix conjugate transpose, matrix inversion, the eigenvalue decomposition, and so on. Algorithm simulation was conducted. Many factors such as direction of arrival (DOA) of interference and polarization estimation error would affect the filtering performance. The simulation results show that the algorithm can effectively suppress interference in dual message signal.