Clayey dolomite is a kind of weakly consolidated sedimentary rock with rich and open holes and high chemical activity from Cenozoic. As a useful environmental engineering material, it deserves further study. This paper discusses the effect and mechanism of the removal of lead ions from aqueous solutions by clayey dolomite. A series of experiments were designed for studying kinetic parameters (time impact), the rate of solid and aqueous concentration, and initial concentration in solutions which may influence and change the effect of removing lead ions. The results show that the equilibrium time of removing lead ions depends on the initial concentration of lead solutions. The equilibrium time is longer when the initial concentration is higher. 100 mg/L lead solution basically demands 70 hours to reach the equilibrium position. In addition, the effect of removal is controlled by final pH. A higher pH value gives rise to a more thorough removal during the process. A higher solid-aqueous rate and higher pH value can improve the removal efficiency. The main mechanism of removal is that lead ions are induced to deposition by clayey dolomite, and meanwhile hydrocerussite is produced after dolomite dissolution.