城市新移民是当前转型中国面临的一个重要问题。这些新移民能否顺利融入新的城市生活，能否如期实现自己的人生目标，直接关系到整个中国社会的经济发展和社会和谐。在众多影响城市外来人口生活质量的因素当中，媒介的作用日益凸显。本研究重点关注了在城市新移民中广泛使用的社交媒体如何影响他们在新环境中的社会融合和幸福感知。基于杭州个案的网络调查数据，本研究发现，社交媒体使用只能在某些方面促进城市新移民的社会融合，其正面作用主要集中在心理上的认同和弱关系的增加，对于深度社会支持的获取和真实社会活动的参与则作用有限。其次，城市新移民的社交媒体使用的确能够影响其主观幸福感，但使用的方式不同，效果也迥异。如果人们更多使用社交媒体进行自我表达，其幸福感会增强；但如果人们更多透过社交媒体来观察社会，其幸福感则会减弱。最后，城市新移民的社会融合程度，尤其是社会认同水平，能够显著影响其主观幸福感。

The growing number of new urban migrants is a critical issue facing the transitional China. Whether these new migrants can adapt to the new city life and achieve their life goals is closely related to the economic development and social harmony of the overall Chinese society. Among all the factors that may influence the quality of life of urban migrants, the role of media is increasingly salient. This study focuses on the impact of social media on new urban migrants’ social integration and subjective well-being. Based on an online survey of urban migrants in Hangzhou, this study revealed that social media use can indeed contribute to urban migrants’ social integration, particularly their perceived social identity and weak social ties, but helps little with strong social support and real world social participation. In addition, while social media use does influence urban migrants’ subjective well-being, different types of use may have different effects. If urban migrants use social media for writing and self-expression, they will feel happier. In contrast, if they use social media for reading and social observation, they will feel less happy. Finally, urban migrants’ social integration, particularly their level of social identity, is significantly associated with their subjective well-being.