The invention discloses an SAR 
echo signal simulation method based on a quasi-double-
station model. The SAR 
echo signal simulation method comprises the following steps: inputting 
simulation parameters, and carrying out parameter initialization, wherein the simulation parameters include an antenna 
phase center triaxial coordinate track [X(ti), Y(ti) and Z(ti)] under an earth-fixed coordinate 
system, a ground target coordinate [xk, yk and zk], a squint angle phi(ti), a look-down angle phi(ti), and a simulation moment tM; calculating a distance vector between an antenna 
phase center to each ground target at each pulse emission moment, pulse receiving moment and pulse transceiving moment according to the simulation moment; and finally, combining with a mathematic model of an SAR 
echo signal, so as to obtain corresponding echo data. According to the method, the high-precision SAR echo simulation can be realized based on the quasi-double-
station model and a continuous motion model of a 
radar; the complicated iterative computation is omitted, and very high computation efficiency is realized when the computational accuracy is guaranteed; and the SAR echo 
signal simulation method is applicable to onboard and 
satellite-bone SAR echo 
signal simulation, and the echo simulation of the SAR echo signals under various conditions can be finished.