Abstract Terrain slope information may be drawn from polarimetric synthetic aperture radar (SAR) two-dimensional image, so that three-dimensional image can be generated. The image data to algorithm discussed in the paper is a key technique to process polarimetric SAR image data to extract terrain slope. The solution fuzzy algorithm of the polarimetric ellipse rotation angle has been proffered and proved in the paper. The target scatter cross-section or signature-peak in the co-polarization signature generates effect of drawing true terrain slope information. Finally, the paper shows the polarimetric SAR three dimensional images from authentic data.