Behavior and mechanism of Ca²⁺ and Fe³⁺ adsorption on spodumene surface were investigated by micro flotation tests, zeta potential measurements, and density functional theory (DFT) calculation methods. The micro flotation tests showed that Ca²⁺ and Fe³⁺ activated the flotation of spodumene remarkably. However, the effect of Fe³⁺ was more significant than that of Ca²⁺. Additionally, Fe³⁺ significantly changed the zeta potential of spodumene while Ca²⁺ showed a little change. Meanwhile, the calculated adsorption energy of Fe³⁺ on spodumene surface was much greater than that of Ca2+ indicating that Fe³⁺ is more apt to be adsorbed on spodumene surface than Ca²⁺. The value of bond population in Ca- O illustrated that the bond of Ca-O consists of partial covalent proportion and some ionic component. On the contrary, the bond of Fe-O showed a relatively strong covalent property. The partial density of states (PDOS) of free Ca/Fe and the reacted O atom on spodumene (110) surface before and after the adsorption showed that Fe 3d orbital and O 2p orbital formed hybridization. The density of states (DOS) near the Fermi level of spodumene surface after adsorption with Fe³⁺ was much stronger than that with Ca²⁺.