Pretreatment technology of natural fiber is the key factor which affects biological composites which are reinforced by natural fiber. First of all

form physical properties

chemical composition and moisture absorption of natural fiber

this article reviews properties of natural fiber. For another

in view of these properties

this article in detail reviews domestic and overseas pretreatment methods of natural fiber and mainly introduces chemical methods of alkaline treatment

silane treatment

permanganate treatment and peroxide treatment

compares the results of natural fiber which is treated by ordinary chemical modification methods; and introduces physical methods of mechanical processing

low temperature plasma technology and steam blasting technology and other biological methods. Finally

this article prospects some existing problems and future development direction of modification technology.