The invention discloses a device and a method for changing a movement track of a grinding medium of a grinding machine based on a magnetic field. The device comprises a base (1), a coil housing (2), a magnet columns (3), coils (4) and a grinding machine barrel body (5), wherein the grinding machine barrel body (5) is mounted in the coil housing (2), and the position of the central axis of the grinding machine barrel body (5) is the same as that of the central axis of the coil housing (2); the grinding machine barrel body (5) can be rotated around the central axis of the coil housing (2); the coil housing (2) is fixedly mounted on the base (1); the magnet columns (3) are uniformly fixed in the coil housing (2) through bolts; the base (1) is fixed to the ground through foundation bolts; the magnet columns (3) are coiled with the coils (4); the magnet columns (3) are arranged in certain angles in a coiling housing barrel body and used for electrifying the coils (4) so as to obtain the magnetic field as requirement. According to the device, the connection of the coils (4) can be changed to obtain the magnetic field in the direction as requirement; the size of the magnetic field can be realized by changing the intensity of current in the coils (4), and thus the movement track of the moving grinding medium in the grinding machine barrel body can be changed.