This study aimed to investigate the role and mechanism of Anctin A, the Antrodia camphorata terpene component, in resisting liver injury. Network pharmacology analysis revealed that MAPK3 was the major action target of Antcin A. Furthermore, experimental research suggested that Antcin A suppressed mouse liver injury, reduced the inflammatory factor levels, and enhanced the anti-oxidative capacity. Meanwhile, it suppressed the expression of MAPK3 and the downstream NF-κB signal, while it did not significantly affect the expression of MAPK1. Based on network pharmacology method, this study discovers that the anti-liver injury effect of Antcin A is mainly related to MAPK3, and that Antcin A can suppress the activation of MAPK3 and its downstream NF-κB to inhibit mouse ALI.