Abstract: ‍ ‍As a product of miniaturized imaging radar， frequency modulated continuous wave synthetic aperture radar （FMCW SAR） has the advantages of simple structure， high imaging resolution and strong system concealment. It needs to be jammed quickly and effectively. In this paper， a partial receiving noise modulation jamming method for FMCW SAR is proposed. The signal time domain is multiplied by the frequency domain of noise template， which can generate a smart suppression area with controllable range. At the same time， the intercepted signal is processed by partial reception， and connect part of the received signal with the head and tail after multiple frequency shift compensation to simulate the full cycle intercepted signal， which avoids the huge data problem caused by sampling FMCW wide-band signal， reduces the signal bandwidth， amount of sampling data and modulation operations. In addition， partial receiving causes sidelobe diffusion of interference， which will disperse part of the energy of the main suppression area. The feasibility of this method is verified by simulation. It can reduce the algorithm complexity and hardware pressure， and realize the smart control of suppression area by changing the time width of the noise template， so it has engineering feasibility.