The Box-Behnken design methodology including five factors: adsorption time, adsorbent dosage, pH, temperature and initial concentration of Pb²⁺ was employed to study the adsorption rate of Pb²⁺ from aqueous solution by humin. A quadratic model for predicting the optimum adsorption conditions was derived which determined the best conditions of adsorption. The adsorption isotherms, thermodynamic property and mechanism were also studied. The study showed that dosing quantity, pH, temperature and initial concentration of Pb²⁺ as significant factors. The adsorption rate reached 92.59% at the optimized conditions of adsorption time 85min, adsorbent dosage 1.2g/L, pH= 4.7, temperature 44.5℃ and initial concentration of Pb²⁺ 202mg/L. The adsorption performance was well fitted with the Langmuir isotherm model, the maximum adsorption capacity presenting 170.28mg/g. And the thermodynamic state function of ΔG⁰、ΔS⁰ and ΔH⁰ were calculated respectively as-29.30~-24.21kJ/mol、126.70J/(mol·K) and 13.59kJ/mol, the adsorption manifesting endothermic process. Active groups on humin such as carbonyl, hydroxyl, amidogen, and carboxyl group participated absorption by complexation with Pb²⁺, accompanied by ion exchange of Ca, Na and Mg ions with Pb²⁺. It is revealed that humin is an potentially green and low-cost absorbent for the treatment of Pb²⁺ contaminated water.