Aiming to solve the problem of collisions that may occur with ships during the operation of the floating dock, which may lead to functional failure or even destruction of the dock, a new collision avoidance device has been researched and designed. Through simulation analysis, the structural response of different collision speeds, different contact areas, and different structural forms of collision avoidance structures under typical working conditions was studied, and the basic law of buffering performance of in-dock collision avoidance devices for floating docks was derived, on the basis of which a new type of in-dock collision avoidance device for floating docks was designed. This study is important to ensure the operational safety and functionality of the floating dock. It can also provide a useful reference for the design of other ship collision avoidance structures.