Aims at the target echo simulation fidelity issues of Radarguided radio frequency hardware in the loop simulation test system, the defects of the traditional approach does not take into account antenna pattern of radar echo simulation are analyzed. Target echo power is modulated by the radar antenna pattern and control algorithm of the simulation test system is improved, a more realistic simulation of target echo power change is realized. Simulation results shows that the method effectively solves the side lobes tracking problem during the test, particularly in the multiple targets situation, the credibility of simulation results is greatly improved.