Magnetic field drive technology has become current research hotspot in the field of micro-robot operation. A gradient-enhanced magnetic field drive system is designed. Firstly, the iron core end model was established, the end shape was designed, and finite element method was used to optimize the iron core coil parameters to meet the system index requirements, such as magnetic induction intensity, magnetic field gradient, magnetic field uniformity and working space. Secondly, the designed magnetic drive system was simulated with ANSYS and tested in experiment. It is concluded that the maximum magnetic induction intensity at the working space center of the magnetic drive system is 73. 93 mT, the maximum magnetic field gradient at the working space center is 8. 68 T/ m. Compared with the gradient magnetic field drive system studied in other literatures, the performance has improved significantly. At the same time, the motion control experiment analysis on the designed new magnetic drive system was conducted. The results show that the system can perform closed-loop position control of the magnetic beads under different environments. The average error for driving the magnetic beads moving along the predetermined trajectories under the silicone oil environment with different viscosity is 0. 066 mm at most, and the maximum root mean square error is 0. 078 mm.