The invention provides a simulation method and device of a radar echo signal. The reality of the radar echo signal simulated by a radar echo signal simulator can be improved from distance to dimension through delay modulation on a radar baseband signal according to delay information of each target scattering point; the reality of the radar echo signal simulated by the radar echo signal simulator can be improved from orientation to dimension through complex multiplying operation on a delay signal of each target scattering point obtained after delay modulation and an antenna amplitude of one corresponding target scattering point and a phase of the target scattering point separately, so that the reality of the radar echo signal obtained through simulation is effectively improved on the premise of meeting two-dimensional high resolution of a synthetic aperture radar to meet an accurate evaluation result of reflecting the performance indicator level of the synthetic aperture radar.