The technical scheme of the bow anchor arrangement is proposed due to the problem of the collision or twist between the bow anchor chain and the submerged body of the small waterplane area twin hull (SWATH). The relative motion between the anchor chain and the hull of the SWATH is studied by the numerical simulation and the model test. The environmental conditions prone to collision are then analyzed to provide reference for the full-scale ship. It is of great significance to improve the mooring efficiency and reduce the collision and twist of the anchor chain.