Abstract: The electromagnet suction head is a key part of the magnetic precision seeder. Improving the seeding efficiency, several electromagnet suction heads were arranged in a row, thus they made up of a multipole magnetism. Therefore, applying the relevant magnetic theory, the calculation model of the magnetic field intensity and magnetic force on the magnetic seed-metering space was developed, and its total characteristic was analyzed. Three kinds of magnetic pole were selected with the forms of round, level and awl shape separately, by the testing of magnetic field and data regression analysis, the magnetic field intensity and magnetic force were obtained different heights of air crack. Studies show that the magnetic force of the electromagnet concentrates on nearby the magnetic pole mainly, the awl magnetic pole is the greatest among them, and its magnetic force performance is optimum.