The invention discloses a ship, an auxiliary propulsion system and an auxiliary propulsion device of the ship. The auxiliary propulsion device comprises blades, a blade guide shaft rod, a drive motorand a motor fixing frame, wherein the blades are arranged on a tail shaft outlet portion of the ship and spaced away from the outer wall of the tail shaft outlet portion at a preset interval; the blade guide shaft rod penetrates through the blades in the length direction and are fixedly connected with the blades; an output shaft of the drive motor is in transmission connection with the blade guideshaft rod, and the drive motor drives the blade guide shaft rod to rotate and drives the blades to rotate within the preset angle range with the blade guide shaft rod as a rotary shaft; and the motorfixing frame is fixedly connected to the inner wall of the tail shaft outlet portion and fixes the drive motor to the tail shaft outlet portion. The auxiliary propulsion device can be a ship propulsion energy-saving efficiency-improvement system, a flow field in front of a propeller is rectified through the blades, the blades freely rotate in the circumferential direction, the attack angle of each blade can be adjusted, and it is guaranteed that the propeller can be in the working state of the optimal propulsion efficiency all the time in various working conditions.