A flat linear oscillation motor comprises an upper cover, a base matched with the upper cover to form a holding space, a coil which contained in the holding space and positioned on the base, an elastic supporting piece connected with the base and a permanent-magnet that is hung in the holding space by the elastic supporting piece; wherein, the base is provided with a plurality of side walls and a bottom wall being vertical to the side walls, the coil is arranged on the bottom wall and positioned in the center under the permanent-magnet, a gap is arranged between the coil and the permanent-magnet, the magnetic pole of the permanent-magnet just faces the coil, and the polarization direction of the magnetic pole of the permanent-magnet facing the coil is opposite, the elastic supporting piece is provided with a fixing part connected with the base, an elastic arm that extends out from and faces the fixing part and has the elastic deformation direction to be parallel to the bottom wall of the base, and a jointing part that extends out from the elastic arm and is connected with the permanent-magnet to lead the permanent-magnet to move along the direction being parallel to the bottom wall.