<p>Mississippi Valley-type (MVT) Zn-Pb deposits contribute considerable amounts of global Zn, Pb, Ag, and associated critical metals such as Ga and Ge. Understanding their ore genesis and developing effective exploration strategies are therefore important issues in economic geology. However, whether extensional or compressional faults are dominant and what role they played in the formation of MVT Zn-Pb deposits is not well understood. To address this, numerical simulations of the Fankou deposit, South China, were conducted under different tectonic conditions. The numerical modeling results show that: (1) the buoyancy resulting from a typical geothermal gradient alone (without tectonic forcing) causes fluids to circulate only within the faults, which is insufficient to focus ore-forming fluids; (2) an appropriate level of compressional deformation promotes the upward migration of ore fluids along the faults, whereas excessive compression (&gt; 2% shortening) can clog fluid migration pathways; (3) extensional deformation leads to weak upward movement of subsurface fluids, but it can effectively concentrate ore fluids from the basement into the aquifer, providing favorable conditions for the subsequent compressional mineralization; and (4) boundary conditions and permeability variations do not alter fluid migration patterns. Separately, each of the four conditions is not sufficient to create large-scale&#xa0;and high-grade MVT deposits seen at the Fankou deposit. However, the combination of the two tectonic conditions, i.e., the episodic extension–compression deformation, is inferred to be the key to the formation of the Fankou deposit, as this combination also has important implications for the formation of fault-controlled hydrothermal deposits.</p>