For the pollution of radioactive materials, it is of great importance to develop efficient adsorbents for radioactive iodine adsorption in aqueous solution. In this work, a simple and green strategy was developed to construct hydrophobic surface on natural cotton fibers (n-CF) based on organic-soluble carbon dots (OCDs) for the first time. The results demonstrated the successful constructed hydrophobic n-CF@OCDs expressed excellent stability and selectivity for iodine (12) adsorption in water. The maximum adsorption capacity for I-2 on n-CF@OCDs is calculated to be 190.1 mg g(-1), which is about 6.8 times higher than that of n-CF (28.1 mg g(-1)), this highly I-2 adsorption efficiency should be attributed to the hydrophobic properties of adsorbent. The adsorption mechanism was also discussed in this work. In addition, the adsorbed I-2 could be desorbed easily with a simple reductive process at ambient conditions, which can lead to not only the restore of I-2 but also the recycling of adsorbent, illustrating their good practicability. Furthermore, this universal strategy can also be used for construction of hydrophobic surface on various natural biomaterials, demonstrating its potential application in constructing of hydrophobic surface and used for the adsorption and removal of nonpolar pollutions or radioactive waste in aqueous solutions.