The invention belongs to the technical field of elastic or flexible bearings or bearing supporting pieces special for rotation movement and particularly discloses a hydraulic ball bearing. The hydraulic ball bearing sequentially comprises a first steel ring, a second steel ring and a third steel ring from inside to outside. The face, opposite to the second steel ring, of the first steel ring is provided with first blades. The second steel ring is provided with balls. A first cavity is formed between the first steel ring and the second steel ring. The first cavity contains hydraulic oil. One end of each ball is arranged inside the hydraulic oil, and the other end of each ball is located between the second steel ring and the second steel ring. The two end faces of an annular channel formed by the second steel ring and the third steel ring are both provided with seal plates. The side, in contact with the seal plates, of the second steel ring is rotationally connected with the seal plates. Compared with the prior art, hydraulic oil has the supporting function and the drive power function at the same time, it is guaranteed that the balls cannot be worn at all, and therefore the service life of the ball is prolonged.