Abstract: The main parameters that have influences on the absorption of heavy metal ions of Pb2+ by the organic modified bentonite were investigated, which includes the types and dosage of the organic modified bentonite, the stirring adsorption time and the the initial pH value of solution. For the treatment of Pb2+ in the wastewater using ZJ-4 the optimal condition is that the initial pH value is 4-9, the dosage of ZJ-4 is 1.0g/L, the absorption time is 15min and the standing time is not less than 5h under the usual temperature. The main reason that there exists the anomaly of the Pb2+ absorption quantity is that the settling of Pb happens. The effect of removing Pb2+ by bentonite mainly depends on the cooperative roles of the settling of Pb and the deep adsorption of bentonite. The majority of Pb2+ in the tapwater was combined with CO2 in the first 5h and precipitated in the form of settling. Besides, the organic modified bentonite can work as flocculant to settle some little particles, reaching the aim of deep treatment collaboratively.