It is very important to build up a kind of complex signal environments by adopting a method of IF injection to improve and train operators under conditions of the complex electric warfare environments. This paper introduces a radar signal environment simulator. First, through analyzing target echoes, deception signals and jamming signals. an overall concept design and a modularization structure design plan for the simulator are proposed, and its performance is tested. The result shows that this simulator can generate echo, deception jamming , chirp jamming signal, barrage jamming, and interruptedspotting jamming signal in realtime, and can switch over them in signal channels. The simulator has a great value for matching the design requirement well, and has practical value.