The utility model provides a test device testing the water shafting power consumption of a ship. The test device comprises a frequency conversion motor (1), a torque meter (3) and a ship shafting, wherein the frequency conversion motor (1), the torque meter (3) and the ship shafting are connected in sequence. The ship shafting is supported by a rolling bearing (6), and passes through a through hole of a water tank (11). The through hole and the ship shafting are sealed by a sealing device. The device can test power consumed by water shaftings of different diameters and rotational speeds.