he new-style urbanization at new era raises high-quality requirement for the citizenization of migrant workers, and the high-quality economic assimilation between the migrant workers and urban workers is the physical basis for their social integration and psychological integration. The analysis using CLDS2014 and CLDS 2016 survey data shows that the possibility of self-employment of the migrant workers with low human capital, long migrating time and much social capital is bigger, that comparing with the employed migrant workers, the self-employed migrant workers have significant economic advantage, are easier to realize economic assimilation with urban workers (average level), and are important group for new-style urbanization. Because the income gap between occupations is bigger than that between household registers, meanwhile, this kind of gap boosts the change of the migrant workers from employed to self-employed, which can narrow the gap between urban area and rural area in China. From the perspective of high-quality economic assimilation, the initial income of self-employed migrant workers is lower than that of urban workers, their income growth rate is slow, as a result, the gap between self-employed migrant workers and urban employed workers is enlarged, the high-quality economic assimilation is difficult to be realized. However, the initial income of employed migrant workers is also lower than urban employed workers, but their income growth rate is faster, the income gap between them and urban employed workers is narrowing, which have the trend of economic assimilation. Self-employed migrant workers are difficult to realize high-quality economic assimilation, which result from lower human capital level, low social capital quality, unperfected urban labor market and so on, and most of them conduct passive survival-style entrepreneurship. Based on that, the public policy should encourage the migrant workers to actively and independently conduct the opportunity-style entrepreneurship, and should use different citizenization policies for self-employed migrant workers and employed migrant workers by raising human capital level and social capital quality of the migrant workers and by perfecting market system and mechanism of labor force and so on.