The invention relates to a method for driving the molten metal to flow three-dimensionally and periodically based on a permanent spiral magnetic field and belongs to the technical field of metallurgical industry. A spiral magnetic field body is manufactured and composed of a plurality of permanent magnet units which are coaxially mounted and are rings, each of the permanent magnet units is composed of a plurality of permanent magnets and a support frame, the plurality of the permanent magnets are evenly embedded in the support frames, magnetization directions of adjacent permanent magnets are opposite, the permanent magnets of adjacent permanent magnet units are staggered at a certain horizontal angle beta successively along an anticlockwise or a clockwise direction, and a rise angle of a composed spiral magnetic field is alpha, so that the molten metal can be placed in a cavity of the spiral magnetic field, the spiral magnetic field rotates at a certain angular speed, rotation directions change alternatively at a certain period, and the molten metal is driven to flow three-dimensionally and periodically. According to the method, various defects in molten metal solidification can be reduced effectively, and the method is applicable in improving the metal solidification process.