The invention belongs to the technical field of bearings, and particularly discloses a seal bearing. The seal bearing comprises an inner ring, an outer ring, a ball and a seal end cover; circular grooves are arranged on two end faces of the outer ring and the inner ring, the ball is arranged between the inner ring and the outer ring, two circular protrusions are coaxially arranged on one end faceof the seal end cover, the seal end cover is arranged on the left and right end faces of the inner ring and the outer ring through the circular protrusions and the circular grooves in the outer ring and the inner ring, a contact inner ring and a contact outer ring are arranged on the contact parts of the inner ring and the outer ring and the ball, and limiting rings are arranged on the inner ringand the outer ring; and an annular boss is arranged at the position, between the inner ring and the outer ring, of the seal end cover, and the portion where the annular boss makes contact with the ball is in an arc shape. Effective seal of the bearing is achieved, meanwhile, the seal end cover can be automatically locked on the inner ring and the outer ring, mounting is convenient, work reliability is high, and lubricating is ensured.