Minqin oasis has an important ecological position in hexi corridor and even the whole country. Remote sensing interpretation was used to study the desertification of land dynamic change characteristics from 1990s to the beginning of this century, and its causes were analyzed. The results indicate; the speed of desert expansion is faster than of oasis recovering speed, and water reduction and sustained large-scale exploitation of groundwater makes oasis faces a greater threat to survival; the development of land desertification in Minqin is the result of many factors, the wind play a major role, so first to rule the wind; there are 66 sandstorm mouths along the 408km sandstorm line in Minqin, how to solve this problem is the fundamental to solve desertification in Minqin.