Tar, a hazardous mixture, produced in biomass gasification can be condensed in the reactor and cause blocking and fouling of engines. Among all the removal technologies, tar removal in the presence of catalyst has been proved to be effective for tar elimination and towards H2-riched syngas production. In recent years, there are many literatures that reported different heterogeneous catalysts in biomass tar reforming, and many catalysts are identified to produce syngas with different compositions. However, further utilization of produced gas (e.g., methanation) is still not well solved, which limited the development of biomass gasification. Hence, in this review, we first reviewed biomass gasification and common methods for produced tar removal. After that, we shed light on the fundamentals (gas clean-up and proportion adjustment) and downstream integration between produced gas from biomass gasification and methanation, etc. Following this, the summary and challenge are concluded to give an insight into the integration between gasification and downstream technologies in the future.