Liquid ammonia treatment can improve the properties of a hemp fiber and widen its application in textiles. This study investigated the effects of different ways of NH3 removal on the fine structure and properties of hemp fibers, including thermal property and dyeing behaviour. It was found that, of the three ways of ammonia removal, removal of ammonia with glacial acetic acid resulted in the highest transition of cellulose Ⅰinto cellulose Ⅲ and removal ammonia with water resulted in the lowest transition of cellulose Ⅰinto cellulose Ⅲ. Removal of ammonia with water also resulted in better thermal stability and higher dye uptake than the other ways of ammonia removal. Of the three ways of ammonia removal, removal of ammonia by evaporation resulted in the lowest dye uptake.