Tree height is a critical biophysical parameter in forestry, and it is closely related to the critical parameters “volume” and “forest biomass” in forest resource management. The detection of tree height has become an important part of ecology and global climate change research, serving as the foundation for monitoring and analyzing the carbon cycle of terrestrial ecosystems and global carbon dynamic change. In this paper, the Digital Surface Model (DSM) is the Digital Elevation Model (DEM) extracted from the short band (C-band) interference image, and the Digital Terrain Model (DTM) is the DEM extracted from the long band (L-band) interference image. The forest height is retrieved using the difference between DSM and DTM based on plane registration, and the forest height change is monitored using multi-phase DSM images, which can be used for large-scale forest height change monitoring. The analysis of the change in tree height in the Helan Mountain Area from 2010 to 2015 to 2020 shows that tree growth is not linear, and the change in tree height also has a decreasing effect with the increase in tree age.