Provided herein is a human monoclonal antibody 8D6 against hepatitis C virus (HCV) infection. The antibody binds to the E2 subunit of HCV capsid protein, and can prevent HCV from infecting susceptible host cells. By using the antibody variable region gene or the complementary determining region (CDR) gene, different forms of genetic engineering antibodies have been transformed and produced in any expression system of the prokaryotic and eukaryotic cells as therapeutics to prevent or treat HCV infection.