Objective: Is the migration process likely to lead to sustained changes in individual social networks and health status? There are many controversies about the relationship between migrants’ networks and migrants’ health. An important reason may be that the constraints of specific social contexts on immigrant networks and health consequences are neglected. This study distinguished two types of social networks of international immigrants to China—their Chinese networks (Chinese-Net) and home-country networks (Motherland-Net). In addition, the study investigated the construction basis of immigrant social networks and health effects based on the Chinese context. Method: A cross-sectional survey was conducted in 2017, 2018, and 2019. The survey was carried out by an on-site questionnaire survey of foreigners in China in the entry-exit hall of the National Immigration Administration. The survey asked foreigners about their immigration experience, labor and employment, social networks, and access to health care. Results and conclusions: Immigrants from more developed countries are more likely to succeed in establishing Chinese-Net and reduce the dependence on Motherland-Net. The Japanese and South Korean immigrants tended to be associated with their home-country compatriots, excluding the Chinese from social contacts and immigration networks. The mixed residence of non-home-country immigrants reduces both the Motherland-Net and Chinese-Net of international immigrants. From the perspective of the health effect, the establishment and expansion of Chinese-Net did not present the “bright side” of encouraging immigrants to reach a better health status. In contrast, Motherland-Net has a stronger explanatory power for the health changes in immigrants.