Abstract: The effects of alkali solution and silane coupling agent on the structure and properties of flax fibers as well as the effect of pretreatment of flax weave with alkali solution and silane on the mechanical properties of flax weave/LLDPE laminate were studied. The experiment results show that the moisture and thermal stability of flax are improved, and the degree of crystallinity and crystal face distance of flax are decreased after the flax weave is treated with alkali solution or silane. The tensile strength is increased from 84.8 MPa to 96.9 MPa, in case the fabric is pretreated with alkali solution;the tensile strength, flexural strength and flexural modulus are increased from 84.8 MPa, 30.1 MPa, 1.95 GPa to 108.9 MPa, 64.6MPa, 7.88 GPa after the flax weave is pretreated with A-151.