The invention discloses a water area elevation processing method for making a DEM (Dynamic Effect Model) based on an INSAR (Interferometric Synthetic Aperture Radar). The water area elevation processing method comprises the following steps: 1, acquiring original measurement data of a region to be measured; 2, carrying out water area elevation processing, namely, performing elevation processing on a static water area and / or flowing water area in the region to be measured, wherein the static water area is processed as follows: 2011, judging level; 2012, processing the level, comprising the steps of I, extracting a bay line; II, assigning an elevation value on the bay line; and III, correcting the water level elevation; and the flowing water area is processed as follows: 2021, judging vertical adjustment; 2022, processing the vertical adjustment, comprising the steps of i, extracting a bay line; ii, assigning a bay line elevation and processing adjustment; iii, constructing an irregular triangular net and an interpolation water level elevation; and iv, correcting a water level elevation. The water area elevation processing method disclosed by the invention is simple in steps, reasonable in design, convenient to realize, good in use effect, and capable of simply and rapidly completing a water area elevation processing process with high quality; the made DEM is high in elevation precision.