Abstract: In order to solve the problems of hemp such as hard handle,easy to crinkle and difficult to dye,the technology of steam explosion is used.The effect of steam explosion treatment on hemp fiber was discussed by analyzing the chemical composition,surface structure,mechanical and dyeing performance of hemp before and after the processing.It was proved that steam explosion processing was favorable for removing pectin,lignin and semi-cellulose,especially for the pectin,which improved the softness and dyeing performance of hemp,but the processing resulted in damage and strength loss of hemp.