To achieve the remote sensing dynamic monitoring of land use in Duolun County, this paper tried to apply knowledge-based remote sensing information extraction technology to this area. Through an in-depth analysis of spectral characteristics, the main cover types were decomposed by the linear spectral mixture model and a number of thematic information models were set up. Extraction rules of all types were set up based on empirical knowledge, and then land use information of Duolun was extracted automatically on a computer. By analyzing the two remote sensing survey results, the information of the land use dynamic changes and conversions between different land use types was obtained. The results show that the previous “three-three” system of land use structure has been broken and the development trend of desertification has been effectively contained. Finally, some proposals on using land rationally are put forward.