Abstract: In order to improve the interfacial adhesion between sisal fiber (SF) and resin matrix,SF surface was treated by alkali,heat,KH-550 silane coupling agent and cyanoethylation,respectively .The sisal fiber/phenol formaldehyde (SF/PF) composite was prepared by compression molding technology after mixing and rolling the treated SF and PF.Effect of surface treatment method on impact strength,bending strength,wear resistance and thermal weightlessness of the composite was studied.And the interface morphology of the composite was observed by SEM.The results show that the interfacial adhesion between SF and PF effectively increased after surface modification.Impact strength of the composite was improved by 34% after alkali method treating of SF.The bending strength was improved by 20% and wear-resistance was improved by 350% after KH-550 method treating of SF.The initial decomposition temperature of the composite increased from 263℃ to 280℃.