Ether-à-go-go-1 (EAG1), one of the potassium channels, is involved in various physiological processes and plays an important role in the tumorigenesis of many kinds of cancer. EAG1 is highly expressed in hepatocarcinoma cells and is closely related to clinical prognosis, but the molecular mechanism remains elusive. In this study, we verified that EAG1 promotes the proliferation of hepatocellular carcinoma (HCC) both in vitro and in vivo. It promotes cell cycle progression by inhibiting the ubiquitination of SKP2. In addition, EAG1 promotes the migration and invasion of HCC by promoting cell pseudopod formation. Furthermore, in a high-pressure plasmid-injected mouse liver orthotopic carcinoma model, astemizole, an EAG family blocker, can significantly inhibit the formation of liver cancer. Meanwhile, liver-specific EAG1 knockout mice show resistance to hepatocarcinogenesis. This research demonstrated that EAG1 plays an important role in the progression of HCC, and could be a potential therapeutic target for HCC.