Using catalytic conversion to reduce the formation of tar in biomass gasification has received great attention, and catalyst improvement is one of the key issues. In this work, Fe-Ni/carbon nanofibers composite materials were prepared and used for tar conversion during biomass gasification. Compared with non-catalyst tar conversion, the tar removal efficiency reached 85.76% and the total syngas yield doubled (0.947 L/g) with Fe-Ni/carbon nanofibers catalyst. After 13-time reuse, the tar removal efficiency and syngas yield only decreased by 7.25% and 9.07%, respectively. Due to the formation of carbon nanofibers through calcination, a high mesopore volume of catalyst was achieved which is beneficial to the adsorption and cracking of macromolecular tar components. And the Fe0.64Ni0.36 alloy detected in Fe-Ni/carbon nanofibers catalyst has a quite high catalytic ability to aromatic compounds. Furthermore, the carbon deposition of catalyst can be relieved by the interaction between Fe and Ni, which can effectively maintain the catalytic performance of catalysts. The combination of bimetallic catalyst with carbon nanofibers allows the high catalytic activity and stable cyclability of Fe-Ni/CNF for effective tar conversion.