The present invention relates to a permanent magnet suitable for a magnetic angle encoder. The permanent magnet has an annular cylindrical structure and comprises a first permanent magnet unit and a second permanent magnet unit. The first permanent magnet unit and the second permanent magnet unit are geometrically symmetrical with respect to a diametral cross section. The magnetization intensity of the first permanent magnet unit and the magnetization intensity of the second permanent magnet unit are parallel to the axial direction of the annular cylinder and are in opposite directions, or the magnetization intensity of the first permanent magnet unit and the magnetization intensity of the second permanent magnet unit are perpendicular to the diametral cross section and are parallel to one another and in the same direction.