The invention discloses a finite difference design method of a magnatic
resonance imaging (MRI)
system gradient coil, which comprises the following steps: firstly, dividing finite difference grids in the coil space, and establishing finite difference relation between a node
stream function and grid
current density on each grid node; subsequently, selecting a constraint
field point in the
magnetic field related region of the MRI
system gradient coil, and computing the magnetic induction intensity on the constraint
field point according to the design requirements; then, establishing a
system of linear equations between the node
stream function and the magnetic induction intensity of the constraint
field point according to the Biot-Savart law; simultaneously, establishing a penalty function of the system of linear equations according to the actual
engineering requirements; and finally, solving the system of linear equations by a method of regularization to acquire a node
stream function value, and determining the current style of the coil by a constant stream function line. The invention is simple and effective and can be suitable for designing gradient coil systems in any structure.