Magnetic drive technology, using the magnetic force produced by permanent magnetic materials or electromagnetic mechanism, realizes the non-contact transfer of force or torque, of which research and application is very wide at the condition of small gap, but is less at the condition of large gap. The external magnetic field drive of permanent magnetic axial blood pump belongs to the category of large gap magnetic drive technology and it is helpful to realize the micromation of blood pump, which has been the research hotspot of blood pump driving technology. However, because the actual magnetic pole gap is much larger than the classical magnetic drive scope, there exists the problem that the system space magnetic field and driving torque decrease rapidly with the increase of magnetic pole gap. Therefore, the research and application of large gap magnetic drive is restricted.Aiming to realize the applications of magnetic drive at the condition of large gap and promote the clinical application of micro axial blood pump, this paper presents a large gap magnetic drive system project, which drives permanent magnetic gear rotate based on the coupling of traveling wave and permanent magnetic gear. The key theories of system drive project, space magnetic field, driving torque and torque-angle characteristic are studied. The large gap magnetic drive system is designed, and the experiment research of system space magnetic field and driving torque is conducted. The research results have instructive value for designing the large gap magnetic drive system which has strong driving ability and is suitable for driving the permanent magnetic axial blood pump and the similar application situation.The main research contents and the corresponding conclusions of this paper are as follows:1. Design and simulation of large gap magnetic drive system projectThe new magnetic drive system project, which can drive the permanent magnetic gear magnetized at the radial direction, is put forward and conducted by the finite element numerical simulation at the condition of large gap. The change law of the system driving torque along with the permanent magnet corner and the design method of magnetic drive system at the condition of large gap are derived. The research results show that magnetic drive system application with strong driving torque at the condition of large gap can be realized by designing the magnetic drive system electromagnet structure and coil electrifying sequence according to the simulation result.2. Research on the space magnet field of large gap magnetic drive systemThe mathematical model of large gap magnetic drive system space magnet field was established and solved under every state of magnetic pole. The distribution law of system space magnet field was revealed. The research results show that permanent magnet can always be in the strong space magnet field which is beneficial to rotation by decreasing the coupling distance of the electromagnet and permanent magnet in the direction of vertical direction and making permanent magnet in the certain space area relatively to electromagnet in the direction of horizontal direction.3. Research on the driving torque of large gap magnetic drive systemThe calculation model of large gap magnetic drive system driving torque was established and solved. The influence law of system main parameter to driving torque was revealed. The research results show that stronger system driving torque can be obtained by increasing the number of windings of coil, the electric current of coil, the permanent magnet outer radius, the permanent magnet magnetization and axial length, by reducing the coupling distance between electromagnet and permanent magnet, and by placing the relative position of the electromagnet and permanent magnet in certain area in x direction (at the left or right side).4. Research on the torque-angle characteristic of large gap magnetic drive systemThe calculation model of torque-angle characteristic of the large gap magnetic drive system under every state of magnetic pole was established and solved. The torque-angle characteristic which indicates the change law about system driving torque along with permanent magnet corner was obtained. The research results show that system torque-angle characteristic curve can be regulated and system driving ability can be increased by changing the electric current and number of windings of coil, the magnetization of permanent magnetic gear, the outer diameter of permanent magnetic gear, and the axial length of permanent magnetic gear.5. Experimental research on the space magnetic field and driving torque of large gap magnetic drive systemWith the theoretical research results used to design the external magnetic field drive system of permanent magnetic axial blood pump and the experiment device made, the experimental research on the space magnetic field and driving torque of large gap magnetic drive system were conducted, which results verified the theoretical results of system space magnetic field and driving torque.