Theory and application study of Frequency Modulated Continuous Wave(FMCW) Synthetic Aperture Radar(SAR) imaging has gained more attention nowadays. Based on Range Doppler Algorithm(RDA), signal characteristic of FMCW SAR was analyzed in details, and aiming at the azimuth matched filtering problem a method named Scene Range Cell Covering Algorithm(SRCCA) was proposed. Simulation results indicate that accurate imaging can be achieved with no effect on calculation load for the scene of large swath. The proposed SRCCA is effective for azimuth compression.