Under the traditional urban-rural dual social structure system, migrant workers have become the special group in the transformation of Chinas modern society.With the fast development of economy and society, more and more workers go to work and do business in cities from rural areas.It is undoubted that migrant workers have made positive contributions to the development of our countrys economy and society, while our country lacks of social security system of the migrant workers for a long time and social security rights is serious deficient.The party and the country attach great importance to the issue of migrant workers social security, and they emphasizes that they should "resolve the social security problems of migrant workers actively and reliably, bring migrant workers into the area of working injury insurance, tackle the medical security of migrant workers serious illness quickly, and discover the endowment insurance which adapts to migrant workers features".Considering all of these, from tidying the policy of migrant workers social security, this article analyzes the problems and causes of present migrant workers social security in the practice and puts forward the responding policy suggestions.