SAR imaging method, device and system

The invention discloses an SAR imaging method including: dividing received first full-aperture SAR echo data into more than two sections of sub-aperture SAR echo data in a azimuth direction and carrying out distance-direction processing on the more than two sections of sub-aperture SAR echo data; combining the more than two sections of sub-aperture SAR echo data which undergo the distance-direction processing into second full-aperture SAR echo data; dividing the second full-aperture SAR echo data into more than two SAR echo-data blocks in the distance direction and processing the more than two SAR echo data blocks in the azimuth direction; and combining the more than two SAR echo-data blocks which undergo the azimuth direction processing into an SAR image. The invention also discloses an SAR imaging device and system. Through adoption of the scheme, high-speed and high-quality imaging processing on the SAR echo data in a large scale is realized with an excellent imaging effect and GPU speed-up ratio.