On account of social capital, this paper explores the influence factors of social media academic search behavior with three aspects about relational capital, structure capital and cognitive capital. The conclusion comes that relational capital positively affects the perceived usefulness of social media academic search behavior; cognitive capital positively influences the perceived usefulness of social media academic search behavior; perceived usefulness shows positive influence on voluntary search willing when people use social media; perceived hedonic positively affects users' voluntary search willing during using social media.