Crystallographic orientations play a crucial part in photoelectric properties of crystalline materials.This paper reported significant enhancement of photoelectric properties in γ-phase copper silver iodide (γ-CuxAg1-xI,0.6≤x≤0.9) films compared with Cu-poor (0.1≤x≤0.4) counterparts due to highly (111)-preferred orientation and larger grains.Transient surface photovoltage (TSPV) spectroscopy reveals that CuxAg1-xI(0.6≤x≤0.9) exhibit faster transferring rate and slower recombination rate than Cu-poor ones.Preferred orientation significantly influenced the photoelectric properties by reducing photocarrier recombination.In X-ray diffraction (XRD) patterns and Rietveld results,it was displayed that CuxAg1-xI (x=0.1~0.9) films exhibit (111) preferred orientation and higher crystallinity when Cu doping content increased.Scanning electron microscope electron channeling contrast imaging (SEM ECCI) analysis demonstrated that (111) most grains with larger size in Cu-rich films compared by Cu-poor were grown with step flow growth mode from (111) preferred prisms defined as basic unit.This paper may provide a valuable basis for CuxAg1-xI applied in photocatalysis or thin film solar cells to achieve higher efficiencies.