In order to monitor human blood flow rate and flow velocity distribution, a blood flow meter based on multi-electrode electromagnetic measurement has been proposed to measure the flow velocity of the arteriovenous blood by obtaining the induced voltage on the skin surface. The COMSOL 3-D model has been built to simulate the physical structure of the human limb, including the size and relative position of skin, fat, bones, muscles, arteries and veins. Based on the Helmholtz coil and C-type coil, the electromagnetic induction intensity distribution of excitation structures and methods is simulated which is imposed through the body measurement section. The optimal design scheme of the excitation coil is proposed. Different excitation systems of different structures and different incentive methods are compared. The result shows that the two pairs of Helmholtz coils of orthogonal layout with syntroph excitation current has better uniformity, field center symmetry and stronger magnetic field strength, and effectively enhances the value of induction electromotive force, showing it is more suitable for multi-electrode electromagnetic measurement of non-axisymmetric flow. The research result proves that the optimization scheme of excitation system is feasible, and its uniformity plays a positive role in improving the accuracy of velocity reconstruction.