The inherent surface limitations of biomass materials restrict their use in high-performance composites, highlighting the need for effective surface modification. Low-temperature plasma technology has emerged as a promising solution owing to its rapid processing, localized energy, and environmental friendliness. This review systematically examines recent advances in the surface modification of biomass materials using low-temperature plasma. First, low-temperature plasma systems are classified and described according to working atmosphere, operating pressure, and discharge mode. Subsequently, the physicochemical mechanisms underlying surface modification are thoroughly discussed. The effect of key process parameters—such as aging effect, discharge power, and treatment distance—on modification outcomes is analyzed. The specific applications and effects of low-temperature plasma technology on typical biomass materials, including wood, bamboo, and straw, are summarized. Studies have indicated that low-temperature plasma treatment significantly enhances the surface properties of biomass materials. With further development, low-temperature plasma technology may gradually replace certain conventional modification methods. Future research should focus on elucidating the structure–property relationships between plasma process parameters and material performance and advancing the technology from laboratory to industrial scale. The integration of artificial intelligence and machine learning provides great potential to accelerate the discovery of process–performance correlations through data modeling and intelligent optimization, enabling precise control and smart manufacturing.

Lignin is a renewable aromatic feedstock for wood adhesives, but its structural heterogeneity complicates control over curing and water resistance. This review examines how lignin structure and functionalization govern curing reactions, kinetics, and crosslinked network development in lignin-based wood adhesives, and how these processes relate to bondline formation and wet bonding performance. Across condensation, epoxy, and polyurethane-based systems, molecular weight, aromatic condensation, and reactive-site accessibility influence lignin incorporation into polymer networks. However, chemical conversion, gelation, and effective network formation do not necessarily proceed in parallel; adhesive flow, penetration, and wood moisture further affect bondline development. Although crosslinking can reduce swelling and improve wet strength, faster curing or higher reactivity does not invariably yield better water resistance. The wet performance of wood joints also depends on network chemical stability, residual hydrophilic groups, interfacial bonding, and moisture-induced deformation and damage. Comparisons among studies remain limited by differences in lignin feedstocks, processing conditions, and water-exposure protocols. Future research should link curing kinetics, network architecture, moisture response, and interfacial failure under controlled testing conditions to establish verifiable structure–property relationships and guide formulation and processing.