In order to study the influence of anti-collision devices on the navigation of bridges in mountainous rivers，a two-dimensional physical model test was carried out to investigate the influence of anti-collision devices on the navigation of ships in the presence of intersection angles between bridges and water currents by analyzing ship navigation parameters such as the bow angle θ and drift angle β using the principle of deviation from the course of a moving ship. By setting up multiple routes，we explore the safe distance between a ship and a bridge pier when sailing. The experimental results show that the impact of anti-collision devices on navigation of river piers in mountainous areas is much greater than that of bare piers，and the impact of anti-collision devices on navigation of ships with pointed bow is greater than that with rounded bow. The larger the angle of intersection between the bridge pier or anti-collision device and current，the larger the deflection range of ship，especially when the angle is 0°-10°，the influence is the largest. Several sets of route navigation tests show that the closer the route is to the bridge pier，the greater the impact on the ship，with this impact peaking when the distance between the route and the pier reaches 3W. The results may serve as reference for the study of safe navigation of mountain river bridges and the research and development of anti-collision devices.