By choosing the mathematical analysis tool, fuzzy consistent matrix, and taking hydropower station B as an example, the social stability risk in the process of land acquisition and resettlement due to construction of hydropower engineering is analyzed, and the importance degrees of various types of risks and the specific risk events in affecting the social stability are measured. The results show that the causes for risks mainly lie in the immigrants and the government administrative departments, the highest type of risks is the compensation benefit risk, and the highest risk factor is the petition channels of immigrants, Therefore, it is suggested that in the period of planning and designing of hydropower engineering, the design institutions should consider the immigrants' vital interests and the potential risks of government management in cooperating with engineering construction so as to make scientific planning and to ensure smooth implementation of the project.