The invention discloses an anti-climbing device of a ship; the outer cover of an object on a fence or a deck on the outer edge of the ship body which is easy to hook is provided with a circular cover body; and the outer surface of the circular cover body is smooth. The outer cover of the fence on the outer edge of the ship body is provided with a closed ring body; and the closed ring body can prevent a hook from hooking into the fence of the ship body, thereby effectively preventing pirates from climbing onto the ship to hijack.