Hydro-morphodynamic patterns in open channel confluences have been extensively studied, but discrepancies exist between flume experiments and field investigations. A standard analog physical model of river confluences is proposed, featuring smooth downstream junction, a large width-to-depth ratio and downstream widening. Flume experiment is conducted on this model to study the hydrodynamic and morphological features within the confluence, which are compared with previous studies. Results show that hydrodynamic and morphological features align with natural confluences but differ from previous flume experiment findings. For instance, typical features in previous flume experiments such as separation zones, and junction corner scour holes are absent in the proposed standard analog model. Results also suggest that strong turbulent kinetic energy and high shear stress within the shear layer are primarily responsible for the formation of mid-channel scour hole. The findings underscore the necessity of employing the standard analog model in future flume experiments related to confluences.