Abstract: Fused deposition modeling (FDM) has become one of the most widely used additive manufacturing (AM) technologies due to its low cost and easy-to-preparation. Also, polylactic acid (PLA) has become the main raw material of FDM filament due to its good biodegradability and biocompatibility. However, the poor brittleness, toughness and heat resistance of PLA have seriously limited the large-scale application of its printing products. Therefore, adding one or more fillers into PLA filament is an important measure to alleviate its own shortcomings. Among them, biomass-based filler is an ideal choice. Adding biomass-based filler into PLA can not only effectively overcome the performance defects of the substrate, but also has good biodegradability and environmental friendliness. This paper reviews the research progress of PLA composites reinforced by the biomass-based filler through FDM printing in recent years. The influence of reinforcing fillers (such as wood powder, natural fiber, nanocellulose) with different size (from micrometer to nanometer) on the properties of PLA-based composites is investigated, which demonstrates the reasons for improving the properties of composites and the mechanism of interfacial compatibility. Finally, the future development of FDM-printed PLA composites is prospected.