在聚乳酸（PLA）复合材料中掺入质量分数0~40%的亚麻纤维，在辊磨挤出（GE）工艺和密炼混合（IM）工艺预混合的基础上使用注塑成型工艺制备亚麻纤维/聚乳酸（PLA）复合材料。结果表明：亚麻纤维的掺入可以显著提高复合材料的力学性能和生物降解性能，对热稳定性无显著影响。使用密炼混合工艺所得的复合材料比辊磨挤出工艺所得材料具有更为优异的力学性能和生物降解性能。40%L/PLA-IM复合材料拥有最优的力学性能及可生物降解性能，其拉伸强度为63.5 MPa，弹性模量为2.56 GPa，弯曲模量为3.49 GPa，冲击强度为5.58 kJ/m²，降解20 d吸水率为126%，降解20 d失重率为84.1%，降解20 d乳酸产量为36.2 mL。使用密炼混合工艺制备亚麻纤维/PLA复合材料具有一定的可行性。

Flax fibers with a mass fraction of 0~40% were incorporated into polylactic acid (PLA) composites. Based on the pre-mixing of grinding extrusion (GE) and internal mixing (IM) processes, injection molding was used to prepare flax fiber/polylactic acid (PLA) composites. The results show that the incorporation of flax fibers can significantly improve the mechanical properties and biodegradability of the composites, with no significant effect on thermal stability. The composites obtained by the IM process have more excellent mechanical properties and biodegradability than those obtained by the GE process. The 40%L/PLA-IM composite has the optimal mechanical properties and biodegradability. The tensile strength is 63.5 MPa, the elasticity modulus is 2.56 GPa, the flexural modulus is 3.49 GPa, the impact strength is 5.58 kJ/m², the water absorption rate after 20 days of degradation is 126%, the weight loss rate after 20 days of degradation is 84.1%, and the lactic acid production after 20 days of degradation is 36.2 mL. The preparation of flax fiber/PLA composites using the IM process is feasible.