The invention discloses a novel self-sealed bearing comprising an upper sleeve cover and a lower sleeve cover, a steel ball supporting seat, a bearing inner sleeve and steel balls; an upper bearing inner sleeve stretching hole is formed in the center of the upper sleeve cover, a lower bearing inner sleeve stretching hole is formed in the center of the lower sleeve cover, and a space formed together by the upper sleeve cover and the lower sleeve cover is a sleeve cover cavity; the steel ball supporting seat is located in the sleeve cover cavity, a supporting seat center hole is formed in the center of the steel ball supporting seat, steel ball accommodating cavities are formed in the upward side of the steel ball supporting seat, and the adjacent steel ball accommodating cavities are partitioned by accommodating cavity partitioning bosses; a shaft hole is formed in the center of the bearing inner sleeve, the upper part of the bearing inner sleeve stretches into the upper bearing inner sleeve stretching hole, the lower part of the bearing inner sleeve stretches into the lower bearing inner sleeve stretching hole, and the outer wall of the bearing inner sleeve is provided with a steel ball raceway; and the steel balls are supported in the steel ball accommodating cavities, the sides, facing to the steel ball raceway, of the steel balls are in contact with the steel ball raceway, an upper steel ball gap is remained between the upper part of the side, back to the steel ball raceway, of each of the steel balls and the inner wall of the upper sleeve cover, and a lower steel ball gap is remained between the lower part of the side, back to the steel ball raceway, of each of the steel balls and the inner wall of the lower sleeve cover. The novel self-sealed bearing is simplified in structure, convenient to mount, capable of meeting the requirement for a high-speed operation condition of a driving shaft and long in service life.