Abstract: The effects of environmental factors such as pH, the concentration of Sargassum fusiforme (S.fusiforme) powder, initial concentration of Pb²⁺, interference ionic strength and temperature on the removal rate and adsorption capacity of Pb²⁺ were studied, with the non-active S.fusiforme as adsorbent. When the initial concentration of Pb²⁺ was 10 mg/L, the adsorption rate of Pb²⁺ by S.fusiforme powder was higher in the range of pH2.0~5.0, and the highest removal rate was 97.05% at pH3.0. The removal rate of Pb²⁺ by S.fusiforme powder increases with the increase of S.fusiforme powder concentration, but the adsorption capacity reacts against it. When the initial concentration of Pb²⁺ was 60 mg/L and the concentration of S.fusiforme powder was 0.5 g/L, the removal rate of Pb²⁺ was up to 94%. The presence of other cations in the solution interferes with the adsorption of Pb²⁺ by S.fusiforme powder, in which Ca²⁺ was more disturbed than Na⁺ and Cu²⁺ was more harmful than Cd²⁺. What's more, the interference of multiple ions in the adsorption was greater than the interference of a single ion, the square root of adsorption capacity and interference ionic strength showed a certain linear relationship, the correlation coefficients were above 0.95.In the range of 20~60℃, an appropriate increase in temperature facilitated the adsorption process. S.fusiforme powder could be used to remove Pb²⁺and showed a good adsorption performance in the adsorption of Pb²⁺.