Abstract: Poverty alleviation relocation migrants have become an important group to prevent large-scale return to poverty. At present, relocated migrants are facing practical problems such as increased employment market risk, reduced livelihood capital stock, and difficulties in increasing family income. Optimizing the internal structure of livelihood capital, giving full play to the combination effect between livelihood capitals, and enhancing the contribution of livelihood capital portfolio to the income of migrants' families are important ways to solve the above problems. Current research in the academic community related to relocation mostly focuses on analyzing the mechanism of migrants' livelihood capital on total household income, and less on empirically exploring the impact of livelihood capital combinations on different sources of household income and their interaction mechanism based on the perspective of structural-functional theory. This paper takes the migrants in large-scale urbanization centralized resettlement areas in Guizhou Province as the research object. Firstly, it measures the livelihood capital of migrant families, and uses OLS and quantile regression to analyze the mechanism between livelihood capital and family income. Then, this paper uses multiple linear regression model to measure the complementary effect and substitution effect between livelihood capital, constructs a matrix analysis model between migrant's family income and livelihood capital types, and uses tobit and logit regression to conduct empirical tests, and analyzes the impact of different livelihood capital types on different types of income under different dimensions. The results show that: (1) The total amount of livelihood capital of migrants helps to increase the level of household income. In the post-relocation era, natural capital has the smallest marginal contribution to household income, while social capital has a negative impact on household income. (2) There is a universal complementary effect between human capital and natural capital and physical capital, social capital and financial capital, and there is a substitution effect between financial capital and social capital. (3) The greater the value of complementary livelihood capital, the higher the wage income and property income of migrant families, families with low complementary and alternative capital mainly maintain their livelihoods by obtaining transfer income.

Key words: large-scale urbanization centralized resettlement area, complementary livelihood capital, substitution livelihood capital, household income structure