To explore the effect of hydroxyapatite (HAP) on the solidification of heavy metals in mining areas, this study conducted the adsorption experiments to study the kinetic adsorption and isothermal adsorption of Cd²⁺ and Zn²⁺ in the soil of Pb-Zn mines with HAP. The results showed that the adsorption of Cd²⁺ and Zn²⁺ increased with the increase of initial concentrations of Cd²⁺ and Zn²⁺; under acidic conditions, the amount of adsorption increased with the increasing pH values; the quasi-second-order kinetic equation could well describe the adsorption process of Zn²⁺ and Cd²⁺, soil adsorption capacities increased with the addition of HAP. In the Zn-Cd coexistence system, when the initial concentration was <20 mg/L, the adsorption of Zn²⁺ and Cd²⁺ in the soil was not significantly different. The competitiveness of the two metal ions was small, and the competition was obvious as the initial concentrations increased. The maximum adsorption capacities of Zn²⁺reached 79%~87% in a single system, while the maximum adsorption capacities of Cd²⁺ was only 57%~72% in a single system. The competitiveness of Zn²⁺ was better than that of Cd²⁺, and Zn²⁺ seriously inhibited the adsorption of Cd²⁺. In summary, HAP could improve the adsorption performance of soil in the mining area, and enhance the adsorption and retention ability of soil to Zn²⁺ in Zn and Cd contaminated soils.