Despite biochar has a good ability in suppressing asphalt fumes, the relationship between the structure of biochar derived from different plant sources and its performance in adsorbing fumes has not yet been explored. In this study, biochar with varying structures and compositions was prepared from cellulose-rich (tea stalks and poplar sawdust) and lignin-rich (coconut shell fiber and loofah sponge) biomass and used as asphalt fume suppressants. Structural characterization revealed that all biochar developed abundant pore structures. Specifically, cellulose-rich biochar featured macro-/mesoporous structures with relatively oxygen-rich surfaces, while lignin-rich biochar exhibited micro-/mesoporous structures with enhanced π-conjugated graphitic frameworks. Asphalt fume adsorption tests showed that, cellulose-based biochar was more effective in adsorbing H₂S and NOₓ, whereas lignin-rich biochar exhibited superior adsorption of VOCs. GC-MS analysis confirmed that cellulose-rich biochar facilitates the adsorption of polar pollutants due to its higher oxygen-rich surfaces, while lignin-rich biochar enhances the adsorption of aromatic pollutants through π–π interactions. Physical property tests of asphalt showed that the macropores of cellulose-rich biochar absorbed more light fractions and promoted an increase in asphaltenes content, significantly enhancing high-temperature performance but having an adverse effect on asphalt ductility.