Abstract: Repeating jammer can generate bulk of active decoys in range and velocity domain，setting great challenge for target detection and track of aerial surveillance radars.The active decoy discrimination method of a new polarization radar system scheme， named dual polarized array radar， is studied.The spatial polarization agility model of dual polarized array antenna is established，and the spatial polarization characteristic differences between target echo and active deceptive signal are analyzed.Then by obtaining spatial polarization characteristic parameter，the corresponding active decoy discrimination algorithm is designed.Finally，simulations are performed to verify and analyze the algorithm validity and performance.The study gives reference for improving the antijamming ability of aerial surveillance radar system.