Research on biomass decomposition and transformation has attracted widespread attention from academia to industry worldwide, aiming to harvest bio-aromatics from the abundant renewable biomass resource. However, the complexity of the structure and composition of biomass makes its conversion into bio-aromatics a very challenging task. Hence, it is necessary to understand in depth the mechanism of biomass conversion to bio-aromatics with higher selectivity. Although considerable progress has been achieved on the development of bio-aromatics from biomass, the detailed process and reaction mechanism for the bioaromatics synthesis has lacked a complete summary. This work reviews the recent advances in the conversion of biomass to bioaromatics, including biomass gasification, pyrolysis, and hydrolytic fermentation, etc. Various biomass sources and biomass-derived model compounds as examples were used to illustrate the effect of different raw materials on the yield of bio-aromatics. Subsequently, this review summarizes the influence of different catalysts on the synthesis of bio-aromatics and the metal-modified HZSM-5 catalysts exhibited a higher bio-aromatics yield compared with those of other catalysts. Finally, the reaction mechanism of biomass to bio-aromatic hydrocarbons via different reaction routes was discussed in detail. The aim is for the conversion mechanism presented in this work to provide a reference for the efficient conversion of bio-aromatics from biomass in the future.