Purpose of this paper is to put forward specific suggestions for migrant workers housing projects in different regions in the Main Land, by comparing and analyzing modes of the current housing patterns and defining the social welfare scope for rural migrant workers. In this paper, methods of tracing and summarizing are mainly adopted, together with basic ideas and measures of welfare economics. The paper first classifies all measures of housing welfare for migrant workers adopted by the local level. Then on the foundation of the theory of welfare economics, positions the migrant workers group in the whole framework of social welfare in China and define the definite scope and objective of public housing projects for them. The third, via Pareto optimal state and ordinal utility theory, evaluate the effectiveness of different housing patterns of migrant workers on the society. At last, considering cost-effectiveness analysis result, researches the suitability of different migrant workers housing modes according to different situations. The paper comes to the conclusion that, there are differences among demands of welfare housing for migrant workers considering regional and industrial features; housing support from local governments should be provided to migrations that cannot afford living in the city; and large-scale government constructions of housing for migrant workers are not suitable to many situations.