Abstract: Based on the framework of sustainable livelihood capital analysis, this paper empirically studies the income effect of post-migration policy based on Regression discontinuities(RD).The empirical results of this article has the following three main findings:first, the immigration policy for involving the group there were significant negative income effect, immigration has involved family than non-migrant family income less than 3000 yuan. Second, relative to engage in more than 4000 yuan in agricultural livelihood family income loss, engaged in non-agricultural livelihood strategies of family has higher adaptability for policy, loss 1800 yuan is far less than the agricultural livelihoods strategy. Third, the immigrants to different income scale families should not be the same.

Key words: engineering migration, backward immigration, regression discontinuities design, income effect