here is a complex multiple feedback mechanism between the man production system and the resource environment. The modern desertification process is caused by improper human activities . In this paper, we take Wushenqi of the Maowusu sand region as the research object and use the relevant theory of systematology to analyze the correlation mechanism between farming,animal husbandry, forestry, industry and population on one side and modern desertification on the other side. We also use the system dynamic method to simulate the development trend of the modern desertification in Wushenqi. The results indicate that in the modern desertification process the change rates of various indices do not remain unchanged, they have clear steps. It may be concluded that combining the control of the population increase speed with the increase of material and technology inputs in agricultural and animal husbandry production, increasing intensive level, and practicing comprehensive management are the main measures to prevent desertification.