In processing of antagonizing active decoy, the Anti-Radiation Missile(ARM) is faced with such a complex signal environment that there are few algorithms can deal with it. A sectional treatment strategy of anti-radiation passive guide is proposed. By analyzing the signal environment of the ARM, the guide procedure has been divided into three stages. Also the seeker’s mission as well as the adopted signal processing algorithm in each stage is indicated. The principle of the proposed strategy is to divide a complex problem into three simple sub problems so that it is scientific and operable. The validity and feasibility of the strategy is verified by simulation.