High-quality indium Hf-doped oxide (IHfO) films were prepared on quartz and ZnSe substrates by RF magnetron sputtering and annealing. The doping ratio of In₂O₃:HfO₂ was 98wt.%:2wt. %. The composition of the film and the photoelectric properties of the 3~5 μm infrared band were tested and analyzed. The effects of annealing temperature, film thickness and oxygen flow rate on the properties of the film were analyzed. The results of XRD, SEM and XPS show that the prepared IHfO film has the stereo-structure of indium oxide. The doping of germanium does not affect the growth direction of indium oxide, but it leads to the decrease of lattice spacing, and the new hybridization of germanium and indium electrons track. The FTIR test results show that the transmittance of IHfO film in the 3~5 μm band decreases with the increase of annealing temperature, and the film deposited on the ZnSe substrate has a more stable transmittance. When the film thickness is 100 nm, the average transmission rate in the 3~5 μm is around 68%. The Hall Effect test results show that with the increase of oxygen flow rate, the resistivity of IHfO film increases gradually, the carrier concentration decreases, and the Hall mobility changes little. The analysis shows that grain boundary scattering is the main factor affecting the mobility of IHfO film. The optimal resistivity of the film is 3.3×10^-2Ω·cm when the oxygen flow rate is 0.3 sccm. Compared with the commercial visible-band Indium Tin Oxide (ITO) thin films, the IHfO thin films prepared in this paper can be better applied in gas detection, infrared guidance and other related fields in the 3~5 μm infrared band.