As one of the leading cases of acute liver failure triggered by excessive Acetaminophen (APAP), breakdown of the antioxidant system, inflammatory response, and inescapable apoptosis following overaccumulation of reactive oxygen species (ROS) play crucial roles in the mechanisms of APAP-induced liver injury (AILI). Therefore, cutting off ROS overproduction at the source is considered promising. Here, manganese Prussian blue nanozymes (MPBZs) with superior antioxidant enzyme-like activity are prepared as an effective strategy for hepatocyte protection, in which MPBZs accumulated in the liver show anti-oxidation properties by scavenging superfluous ROS. Importantly, in addition to alleviating oxidative stress, bioactive MPBZs with abundant variable valence states as a natural antioxidant enzymes mediated the responses of multi-biological signaling pathways in vitro and in vivo, including Nrf2-Keap1, NF-κB, and mitochondrial-induced apoptosis signaling pathways, enhancing tolerance for imminent AILI. Taking nanomedicine, hepatology, and catalytic chemistry into consideration, the revealed superior performance of AILI prevention suggests that MPBZ-based nano-detoxification therapy may offer an effective alternative against AILI.