In this research, we used anodic aluminum oxide (AAO) nanoporous membranes to produce high-density and high-regularity zinc–indium oxide nanowires, and in the process, the production control parameters could be manipulated to adjust the diameter and distribution of the nanopores on the AAO membranes to produce one-dimensional zinc–indium oxide nanowires with high aspect ratios. A vacuum die casting method was used to fill the alloy into the high aspect ratio holes to form nanowires. The prepared nanowires were soaked in sodium hydroxide solution for wet etching to remove AAO membrane. Then, the nanowires were subjected to oxidation treatment to become zinc–indium oxide nanowires, so as to increase the detectable area of the metal oxide semiconductor sensor for carbon monoxide gas as well as to plate the electrode finishing components. In the experiment, the zinc–indium bulk was subjected to differential scanning calorimetry (DSC) to determine its melting point. Scanning electron microscopy (SEM) was used for the microstructural analysis of the zinc–indium nanowires. Finally, the gas sensing properties of the zinc–indium oxide nanowires were tested by exposing the device to carbon monoxide gas and determining its sensitivity and response time.