Abstract: Worldeconomic crisis in 1929~1933 shattered the market automatically equilibrium theory, Keynesian state interventionism emerged. Roosevelt's New Deal is a bold practice on state interventionism in the economic crisis situation. State interventionism, formed around a various theoretical system and proposition about the thought of state interventionism, and its main contents are weaken private economic activity, advocating the state intervene and participate in the socio-economic activities, to some extent, assume a variety of production, exchange and distribution functions. State interventionism is not only a theoretical system, but also a series of policy proposals established on a theoretical system. Based on the analysis of Roosevelt's New Deal, illustrated the history of state interventionism in the social security ideology, as well as the construction of the social security system affected by the state interventionism.