Adsorption techniques have been successfully applied in water purification because of their flexibility, simplicity of design, and effectiveness. Activated carbon is an effective absorbent using for dye adsorption; however, the powder structure is not conducive for practical applications and cannot be used to filter dye solutions which are challenges that still need to be addressed. Herein, a natural cellulose-based absorbent, activated carbon-Juncus effusus fiber (AC-JE fiber), demonstrates the removal of all kinds of dyes without selectivity and humic substances and humic-like organics from wastewater. The combined macroporous structures of JE fibers and the microporous and mesoporous structures of activated carbon particles enhance their adsorption properties. These composite absorbents have excellent adsorption and continuous filtration effect. The rejection rate is approximately 100% not only on acidic and anionic dyes but also on basic and cationic dyes. Moreover, the dye solution adsorbed by AC-JE fibers exhibits an ideal freshwater quality (almost no bacteria), similar to that of the deionized water. The AC-JE fibers prove their potential for dye removal, in both adsorption and filtration. Their sterilization ability substantiates their potential in the field of water purification as they can be used as ideal absorbents based on cellulose for removing dyes and purifying wastewater.