The invention provides a ship hydrodynamic energy-saving device installed on the front of the exit of a
hull tail shaft. The ship hydrodynamic energy-saving device is characterized by comprising a larboard flow guide
pipe, a starboard flow guide
pipe, a larboard deflector, a starboard fluid deflector and an intermediate reinforcement structure, wherein the larboard flow guide
pipe and the starboard flow guide pipe are arranged on the two sides of a
hull tail part on the front of the exit of a ship
tail shaft, the lower ends of the flow guide pipes are directly connected to a
hull, the upper ends of the flow guide pipes are connected to the deflectors and the intermediate reinforcement structure, and the deflectors and the intermediate reinforcement structure are connected to the hull. A deflector plate type annular guide pipe of the invention can effectively improve the wake flow field of a ship, the surface of the guide pipe can generate thrust force, the output power of a
host machine at the same speed is reduced, the vibration performance of a
propeller is improved, and better energy saving effect is achieved. The device has a simple and reliable structure, is easy to install and maintain, has a good energy-saving effect, and is easy to install on an existing ship.