In the process of jet weaving, airflow plays a primary role by carrying the weft yarns and interlacing them with the warp yarns to form the fabric. The vortex characteristics within the weft insertion channel of an air-jet loom directly affect the motion of the weft yarns, thus impacting the quality of the fabric. In this study, the large eddy simulation (LES) method was employed, and the Omega vortex identification criterion was used to analyze the vortex characteristics within the profile reed channel. The effects of different positions of relay nozzles, nozzle spacing, and reed gap ratio on the airflow characteristics were investigated. Additionally, the vortex volume ratio () and velocity fluctuation rate () were introduced as indicators to measure the proportion of vortices and the turbulence intensity of the airflow field. The numerical results indicated that the introduction of relay nozzles significantly reduced the intensity of airflow vortices and the proportion of vortices within the profile reed channel. When the inlet pressures of the main and relay nozzles were fixed, the minimum values of and were observed when the first relay nozzle was located at 105 mm, the nozzle spacing was 65 mm, and the gap ratio was 1:2. The findings of this study provide theoretical guidance for further improving the airflow characteristics within the profile reed channel of an air-jet looms.