The invention discloses a mountain area SAR image transmission tower detection method considering a terrain. The method comprises the following steps that for an original single-polarized SAR image set, a corresponding average radar power image is calculated; meanwhile, by means of external elevation data, a range direction slope angle image is generated; a quantitative relation of average radar power and the range direction slope angle is estimated, and a power image related to the terrain is simulated by means of the obtained relation; the simulated power image and a real power image are subjected to differencing, and after a terrain influence is reduced, a radar power image is obtained; double-parameter constant false alarm detection is conducted on a target on the radar power image obtained after the terrain influence is reduced, and a binary image is obtained; the binary image is subjected to target pixel clustering analysis, and extraction is conducted according to linear arrangement features. Accordingly, by means of an elevation data simulation amplitude image, the influence of the terrain in a single-polarized SAR image is effectively eliminated, a ground object target ishighlighted, and the accuracy of detection is improved by means of a linear extraction and clustering algorithm.