本文依托媒体政治传播理论，构建有调节的中介效应模型，探索中国主流媒体对民众 政治支持的影响机制，并通过大样本网民调查数据进行实证分析。研究发现:(1)主流媒体使用对政治支持的正向作用路径部分是以形塑使用者的官方意识形态立场为中介的; (2)威权人格弱化了主流媒体使用者意识形态立场的中介作用;(3)主流媒体使用、使用者意识形态立场与政治支持的关系具有较强异质性。未来还需引入前沿政治传播理论，构建更加细化的分析框架，深化中国主流媒体使用之于民众政治支持作用机制的研究。

Relying on the theory of media political communication, this paper explores the influence mechanism of Chinese mainstream media use on popular political support, constructs a moderated mediating effect model, and conducts empirical analysis through large-sample netizen survey data. It is found that, firstly, the positive path of mainstream media use to popular political support is partly mediated by shaping the official ideological position of users. Secondly, authoritarian obedience personality weakens the mediating role of mainstream media users’ official ideological positions. Thirdly, the relationship between mainstream media use, users’ ideological positions and popular political support is heterogeneous. In the future, it is necessary to introduce cutting-edge political communication theories, build a more detailed analysis framework, and deepen the research on the mechanism of popular political support used by Chinese mainstream media.