Radar altimeter echo simulation system is used to simulate the real working scene of various radar altimeter systems, and completes the output of the echo excitation signal of radar altimeter under complex working conditions, and is used for the evaluation of various performance of radar altimeter. The simulation system can simulate the echo of the radar altimeter, the echo of the surface target, the multiple travel simulation of the radar echo in the landing stage of the aircraft, the echo simulation of the radar altimeter under the flight attitude, the forward and backward Doppler simulation and the antenna direct wave signal simulation. It is used for altimeter height measurement performance test or altimeter control or integrated monitoring system test;