The RNG k-ε turbulence model was used to simulate and analyze the open channel flow with patchy distributed double-layer rigid vegetation. The flow velocity and turbulence parameters of the open channel flow with vegetation were statistically analyzed based on the double-average method of time and space. The results show that the open channel flow with patchy distributed vegetation can be divided into vegetation zone, gap zone, and mainstream zone, and the magnitude and distribution of time-averaged flow velocity vary in different zones. In the open channel flow with double-layer vegetation, the vertical distribution of time-averaged flow velocity exhibits inflection points near the bed surface, near the top of the low plants, and near the top of the high plants, and the maximum values of fluctuation intensity and turbulence kinetic energy occur near the top of the high plants.