Magnet with low pole-arc coefficient and manufacturing method thereof

The invention discloses a magnet with the low pole-arc coefficient and a manufacturing method thereof. The magnet is in a hollow cylinder shape. The outer surface or the inner surface of the magnet is magnetized to form the multi-pole magnet, n magnetic poles are formed, and the magnetic field near each magnetic pole is converged towards the magnetic pole in direction, wherein n is an integer number larger than or equal to two. As the magnet with the low pole-arc coefficient is provided, the use efficiency of a permanent magnet is improved, and therefore a system has the low rotating inertia and the good rapid response performance.