The enrichment and separation method was used in the present paper to overcome the influence of matrix effect on the determination of lead concentration and isotope ratios. The patented method was used to enrich and separate the lead in simulated blood matrix; the lead concentrations and isotope ratios were determined by ICP-MS before and after enrichment and separation. The recovery rate of Pb is more than 99% through this method while the removal rate of major impurity ions such as Na, K is about 80%. The concentrations of each lead isotope decrease with the matrix concentration increasing (p<0.001), and lead isotope ratios show no significant differences in the matrix of different concentrations. When the matrix concentration is more than 62.5 μg·mL-1, the strength will decrease with the determination times increasing. It was concluded that the characteristics of this method are of high recovery rate (>99%), fast, simple and convenient, and it can raise the accuracy and precision of the concentration determination of lead isotopes and has no significant influence on the accuracy of lead isotope ratios determination.