With Loffeld's bistatic formula (LBF), the transfer function of the multireceiver synthetic aperture sonar (SAS) can be decomposed into the quasi-monostatic term and bistatic deformation term. For this model, the phase error in the 2D frequency domain is quantitatively analyzed. The results indicate that this model can fully satisfy the imaging need with high performance. Based on that, a new imaging method is proposed. Firstly, the range variant term of bistatic deformation phase should be first compensated in the 2D frequency domain via the range-dependent sub-block processing. Subsequently, the monostatic SAS equivalent data can be obtained by rearranging the multireceiver data in order in the 2D time domain. Then, a range-Doppler (R-D) algorithm is exploited to process the monostatic SAS equivalent data. Finally, the processing results of simulated and real data validate the proposed method.