Poverty and anti-poverty is still a major theoretical and practice topic faced by China. In order to achieve the goal of building of a well-off society in an all-round manner by 2020，making 70 million people cast off poverty is a major political task of the Party and government. Poverty-alleviation development and social-security-based anti-poverty are two major efficient instruments. This paper，from the angle of social security，analyzes and researches the functional mechanism of social security system in anti-poverty，and uses survey data to verify the function and role of the social security system for the minority-concentrated region in narrowing income gap and improving anti-poverty effect. The research shows that anti-poverty effect of the social security system exists objectively，with rural social security system seeing more obvious anti-poverty effect；the people and the officials are overall satisfied with social security-based anti-poverty. Of course，anti-poverty effect of the social security system in the minority-concentrated region is still low generally，and challenges and problems in the social security system allow of no neglect. The paper，combining international experience and actual situations of China，points out the thinking and recommendations for improving the social security system in the “13^th Five-Year-Plan” period.