Using Pomelo peel’s pulp (PPP) as raw materials, the new chemically modified PPP was prepared by the process of fermentation, cooking, freeze-drying, and so on. The adsorbent were characterized by SEM, IR, BET and EDS. The effects of different adsorption conditions such as pH value, adsorption temperature, mass of adsorbent, adsorption time, and initial concentration of UO22+ were studied. The adsorption mechanism was explored through adsorption thermodynamics and adsorption kinetics experiments. The results show that the pH value is 6.0, the dosage of adsorbent is 10 mg, the temperature is 50℃ and the adsorption time is 90 min, which is the best adsorption condition. When the initial concentration of UO22+ is 35 mg/L, the adsorbed capacity of uranyl ion by the modified PPP adsorbent can reach 42.733 mg/g, 26.8% higher than the adsorption capacity of unmodified adsorbent (31.276 mg/g), which is obviously enhanced. The kinetic and thermodynamic experiments show that the adsorption process accords with the pseudo-second-order kinetics model and is an endothermic reaction, and the reaction is spontaneous. The adsorption process is dominated by entropic. The Freundlich adsorption isotherm can describe the adsorption process more accurately.