The invention discloses a ship beaching auxiliary device and method. The auxiliary device comprises a laser generator and an optical emitting and receiving device. Information transmission is conducted between the information output end of the laser generator and the optical emitting and receiving device through a laser optical fiber transmission system. Information transmission is conducted between the information output end of the optical emitting and receiving device and an information detecting and information processing system which is connected with a display terminal. The ship beaching auxiliary device and method have the advantages of being capable of obtaining the condition of underwater landforms of water areas and shores where a ship is about to arrive, enabling ships to put down a primary door to arrive in beaches smoothly, being capable of ensuring that persons and vehicles disembarking the ships to arrive in beaches safely. Consequently, the device and method provide auxiliary decision information for operation of vehicle ferries and landing boats at beaching time and disembarking of vehicles and persons, greatly improve ship beaching reliability, ensure safety of vehicles and persons at disembarking time, and completely eliminate potential safety hazards of ship beaching in any condition.