<p>The scattered metal germanium (Ge) often exists in sphalerite via multiple substitution mechanisms, forming Ge-bearing sphalerite. This paper aims to investigate the effects of four different Ge substitution mechanisms on the crystal structure and electronic properties of sphalerite using density functional theory (DFT), namely: (1) Zn²⁺↔Ge²⁺, (2) 2Zn²⁺↔Ge⁴⁺+vacancy, (3) 3Zn²⁺↔Ge⁴⁺+2Cu⁺, and (4) 3Zn²⁺↔Ge⁴⁺+Fe²⁺+vacancy. The results indicate that the four forms of Ge substitution mechanisms introduce impurity energy levels into the forbidden band interval of sphalerite, leading to a significant decrease in band gap and an enhancement of electrical conductivity. And the impurity energy levels are mainly contributed by atomic orbitals of Ge 4s, Cu 3d, and Fe 3d. The Ge—S bonds in (1)-type Ge-bearing sphalerite exhibit weak covalency, while those in the other three types of Ge-bearing sphalerite show significantly stronger covalency. Frontier orbital analysis suggests that all four forms of Ge substitution mechanisms enhance the interaction between sphalerite and butyl xanthate, with the order of interaction intensity being: (4)-type&gt;(3)-type&gt;(2)-type &gt;(1)-type≈ideal sphalerite.</p>