Taking remote sensing data as the main information source, through massive field investigation, the paper established the image translation signs of different types of land utilization and vegetation coverage. Under the support of geographic information system, by the method of computer assistanted artificial translation, it has carried on the soil erosion dynamic monitoring to the Hekou town-Longmen sector. The result show: About 80.40% of total soil erosion was water erosion; about 19.60% was wind erosion. The soil erosion intensity is mainly determined by moderate erosion and intensive erosion, the micro-degree erosion take second part, the third is mild erosion and extremely intensitive erosion, the acute erosion accounts for the smallest proportion. Compared with the soil erosion in 2000 the total soil erosion intensity reduced in 2008. The areas of micro-degree erosion, mild erosion and moderate erosion increased gradually; the areas of extremely intensitive erosion and acute erosion decreased accordingly. It shows that the eco-environment improves gradually in this area. The erosion is turning toward the benign tendency. Except for the reason that terraced field, forest land and dam land takes more and more environmental benefit, perhaps the increase of grass land, especially the implementation of large area closing measures and ecological restoration is the main reason that weakened the soil erosion intensity in this sector in recent years.