With respect to error range of Anti Radiation Missile (ARM) under active decoy interference, the solutions to improve the performance of ARM under interference are put forward; To satisfy the requirement of angular resolution, set the model of 2D-DOA estimation based on UCA, and discuss the implement of the algorithm in Passive Radar Seeker (PRS); Computer simulation indicates that 2D-DOA estimation algorithm based on UCA can meet the need of angular resolution.